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2022-09-15debugfs: add debugfs_lookup_and_remove()Greg Kroah-Hartman
commit dec9b2f1e0455a151a7293c367da22ab973f713e upstream. There is a very common pattern of using debugfs_remove(debufs_lookup(..)) which results in a dentry leak of the dentry that was looked up. Instead of having to open-code the correct pattern of calling dput() on the dentry, create debugfs_lookup_and_remove() to handle this pattern automatically and properly without any memory leaks. Cc: stable <stable@kernel.org> Reported-by: Kuyo Chang <kuyo.chang@mediatek.com> Tested-by: Kuyo Chang <kuyo.chang@mediatek.com> Link: https://lore.kernel.org/r/YxIaQ8cSinDR881k@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-15USB: core: Prevent nested device-reset callsAlan Stern
commit 9c6d778800b921bde3bff3cff5003d1650f942d1 upstream. Automatic kernel fuzzing revealed a recursive locking violation in usb-storage: ============================================ WARNING: possible recursive locking detected 5.18.0 #3 Not tainted -------------------------------------------- kworker/1:3/1205 is trying to acquire lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 but task is already holding lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 ... stack backtrace: CPU: 1 PID: 1205 Comm: kworker/1:3 Not tainted 5.18.0 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: usb_hub_wq hub_event Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain kernel/locking/lockdep.c:3816 [inline] __lock_acquire.cold+0x152/0x3ca kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5630 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x14f/0x1610 kernel/locking/mutex.c:747 usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 usb_reset_device+0x37d/0x9a0 drivers/usb/core/hub.c:6109 r871xu_dev_remove+0x21a/0x270 drivers/staging/rtl8712/usb_intf.c:622 usb_unbind_interface+0x1bd/0x890 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:545 [inline] device_remove+0x11f/0x170 drivers/base/dd.c:537 __device_release_driver drivers/base/dd.c:1222 [inline] device_release_driver_internal+0x1a7/0x2f0 drivers/base/dd.c:1248 usb_driver_release_interface+0x102/0x180 drivers/usb/core/driver.c:627 usb_forced_unbind_intf+0x4d/0xa0 drivers/usb/core/driver.c:1118 usb_reset_device+0x39b/0x9a0 drivers/usb/core/hub.c:6114 This turned out not to be an error in usb-storage but rather a nested device reset attempt. That is, as the rtl8712 driver was being unbound from a composite device in preparation for an unrelated USB reset (that driver does not have pre_reset or post_reset callbacks), its ->remove routine called usb_reset_device() -- thus nesting one reset call within another. Performing a reset as part of disconnect processing is a questionable practice at best. However, the bug report points out that the USB core does not have any protection against nested resets. Adding a reset_in_progress flag and testing it will prevent such errors in the future. Link: https://lore.kernel.org/all/CAB7eexKUpvX-JNiLzhXBDWgfg2T9e9_0Tw4HQ6keN==voRbP0g@mail.gmail.com/ Cc: stable@vger.kernel.org Reported-and-tested-by: Rondreis <linhaoguo86@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/YwkflDxvg0KWqyZK@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-15usb: typec: altmodes/displayport: correct pin assignment for UFP receptaclesPablo Sun
commit c1e5c2f0cb8a22ec2e14af92afc7006491bebabb upstream. Fix incorrect pin assignment values when connecting to a monitor with Type-C receptacle instead of a plug. According to specification, an UFP_D receptacle's pin assignment should came from the UFP_D pin assignments field (bit 23:16), while an UFP_D plug's assignments are described in the DFP_D pin assignments (bit 15:8) during Mode Discovery. For example the LG 27 UL850-W is a monitor with Type-C receptacle. The monitor responds to MODE DISCOVERY command with following DisplayPort Capability flag: dp->alt->vdo=0x140045 The existing logic only take cares of UPF_D plug case, and would take the bit 15:8 for this 0x140045 case. This results in an non-existing pin assignment 0x0 in dp_altmode_configure. To fix this problem a new set of macros are introduced to take plug/receptacle differences into consideration. Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") Cc: stable@vger.kernel.org Co-developed-by: Pablo Sun <pablo.sun@mediatek.com> Co-developed-by: Macpaul Lin <macpaul.lin@mediatek.com> Reviewed-by: Guillaume Ranquet <granquet@baylibre.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Pablo Sun <pablo.sun@mediatek.com> Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com> Link: https://lore.kernel.org/r/20220804034803.19486-1-macpaul.lin@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-15platform/x86: pmc_atom: Fix SLP_TYPx bitfield maskAndy Shevchenko
[ Upstream commit 0a90ed8d0cfa29735a221eba14d9cb6c735d35b6 ] On Intel hardware the SLP_TYPx bitfield occupies bits 10-12 as per ACPI specification (see Table 4.13 "PM1 Control Registers Fixed Hardware Feature Control Bits" for the details). Fix the mask and other related definitions accordingly. Fixes: 93e5eadd1f6e ("x86/platform: New Intel Atom SOC power management controller driver") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220801113734.36131-1-andriy.shevchenko@linux.intel.com Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-15fs: only do a memory barrier for the first set_buffer_uptodate()Linus Torvalds
commit 2f79cdfe58c13949bbbb65ba5926abfe9561d0ec upstream. Commit d4252071b97d ("add barriers to buffer_uptodate and set_buffer_uptodate") added proper memory barriers to the buffer head BH_Uptodate bit, so that anybody who tests a buffer for being up-to-date will be guaranteed to actually see initialized state. However, that commit didn't _just_ add the memory barrier, it also ended up dropping the "was it already set" logic that the BUFFER_FNS() macro had. That's conceptually the right thing for a generic "this is a memory barrier" operation, but in the case of the buffer contents, we really only care about the memory barrier for the _first_ time we set the bit, in that the only memory ordering protection we need is to avoid anybody seeing uninitialized memory contents. Any other access ordering wouldn't be about the BH_Uptodate bit anyway, and would require some other proper lock (typically BH_Lock or the folio lock). A reader that races with somebody invalidating the buffer head isn't an issue wrt the memory ordering, it's a serialization issue. Now, you'd think that the buffer head operations don't matter in this day and age (and I certainly thought so), but apparently some loads still end up being heavy users of buffer heads. In particular, the kernel test robot reported that not having this bit access optimization in place caused a noticeable direct IO performance regression on ext4: fxmark.ssd_ext4_no_jnl_DWTL_54_directio.works/sec -26.5% regression although you presumably need a fast disk and a lot of cores to actually notice. Link: https://lore.kernel.org/all/Yw8L7HTZ%2FdE2%2Fo9C@xsang-OptiPlex-9020/ Reported-by: kernel test robot <oliver.sang@intel.com> Tested-by: Fengwei Yin <fengwei.yin@intel.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05mm/rmap: Fix anon_vma->degree ambiguity leading to double-reuseJann Horn
commit 2555283eb40df89945557273121e9393ef9b542b upstream. anon_vma->degree tracks the combined number of child anon_vmas and VMAs that use the anon_vma as their ->anon_vma. anon_vma_clone() then assumes that for any anon_vma attached to src->anon_vma_chain other than src->anon_vma, it is impossible for it to be a leaf node of the VMA tree, meaning that for such VMAs ->degree is elevated by 1 because of a child anon_vma, meaning that if ->degree equals 1 there are no VMAs that use the anon_vma as their ->anon_vma. This assumption is wrong because the ->degree optimization leads to leaf nodes being abandoned on anon_vma_clone() - an existing anon_vma is reused and no new parent-child relationship is created. So it is possible to reuse an anon_vma for one VMA while it is still tied to another VMA. This is an issue because is_mergeable_anon_vma() and its callers assume that if two VMAs have the same ->anon_vma, the list of anon_vmas attached to the VMAs is guaranteed to be the same. When this assumption is violated, vma_merge() can merge pages into a VMA that is not attached to the corresponding anon_vma, leading to dangling page->mapping pointers that will be dereferenced during rmap walks. Fix it by separately tracking the number of child anon_vmas and the number of VMAs using the anon_vma as their ->anon_vma. Fixes: 7a3ef208e662 ("mm: prevent endless growth of anon_vma hierarchy") Cc: stable@kernel.org Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05netfilter: ebtables: reject blobs that don't provide all entry pointsFlorian Westphal
[ Upstream commit 7997eff82828304b780dc0a39707e1946d6f1ebf ] Harshit Mogalapalli says: In ebt_do_table() function dereferencing 'private->hook_entry[hook]' can lead to NULL pointer dereference. [..] Kernel panic: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] [..] RIP: 0010:ebt_do_table+0x1dc/0x1ce0 Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 5c 16 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 6c df 08 48 8d 7d 2c 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 88 [..] Call Trace: nf_hook_slow+0xb1/0x170 __br_forward+0x289/0x730 maybe_deliver+0x24b/0x380 br_flood+0xc6/0x390 br_dev_xmit+0xa2e/0x12c0 For some reason ebtables rejects blobs that provide entry points that are not supported by the table, but what it should instead reject is the opposite: blobs that DO NOT provide an entry point supported by the table. t->valid_hooks is the bitmask of hooks (input, forward ...) that will see packets. Providing an entry point that is not support is harmless (never called/used), but the inverse isn't: it results in a crash because the ebtables traverser doesn't expect a NULL blob for a location its receiving packets for. Instead of fixing all the individual checks, do what iptables is doing and reject all blobs that differ from the expected hooks. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com> Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-05kernel/sched: Remove dl_boosted flag commentHui Su
commit 0e3872499de1a1230cef5221607d71aa09264bd5 upstream. since commit 2279f540ea7d ("sched/deadline: Fix priority inheritance with multiple scheduling classes"), we should not keep it here. Signed-off-by: Hui Su <suhui_kernel@163.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Link: https://lore.kernel.org/r/20220107095254.GA49258@localhost.localdomain [Ankit: Regenerated the patch for v4.19.y] Signed-off-by: Ankit Jain <ankitja@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05sched/deadline: Fix priority inheritance with multiple scheduling classesJuri Lelli
commit 2279f540ea7d05f22d2f0c4224319330228586bc upstream. Glenn reported that "an application [he developed produces] a BUG in deadline.c when a SCHED_DEADLINE task contends with CFS tasks on nested PTHREAD_PRIO_INHERIT mutexes. I believe the bug is triggered when a CFS task that was boosted by a SCHED_DEADLINE task boosts another CFS task (nested priority inheritance). ------------[ cut here ]------------ kernel BUG at kernel/sched/deadline.c:1462! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 12 PID: 19171 Comm: dl_boost_bug Tainted: ... Hardware name: ... RIP: 0010:enqueue_task_dl+0x335/0x910 Code: ... RSP: 0018:ffffc9000c2bbc68 EFLAGS: 00010002 RAX: 0000000000000009 RBX: ffff888c0af94c00 RCX: ffffffff81e12500 RDX: 000000000000002e RSI: ffff888c0af94c00 RDI: ffff888c10b22600 RBP: ffffc9000c2bbd08 R08: 0000000000000009 R09: 0000000000000078 R10: ffffffff81e12440 R11: ffffffff81e1236c R12: ffff888bc8932600 R13: ffff888c0af94eb8 R14: ffff888c10b22600 R15: ffff888bc8932600 FS: 00007fa58ac55700(0000) GS:ffff888c10b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa58b523230 CR3: 0000000bf44ab003 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? intel_pstate_update_util_hwp+0x13/0x170 rt_mutex_setprio+0x1cc/0x4b0 task_blocks_on_rt_mutex+0x225/0x260 rt_spin_lock_slowlock_locked+0xab/0x2d0 rt_spin_lock_slowlock+0x50/0x80 hrtimer_grab_expiry_lock+0x20/0x30 hrtimer_cancel+0x13/0x30 do_nanosleep+0xa0/0x150 hrtimer_nanosleep+0xe1/0x230 ? __hrtimer_init_sleeper+0x60/0x60 __x64_sys_nanosleep+0x8d/0xa0 do_syscall_64+0x4a/0x100 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fa58b52330d ... ---[ end trace 0000000000000002 ]— He also provided a simple reproducer creating the situation below: So the execution order of locking steps are the following (N1 and N2 are non-deadline tasks. D1 is a deadline task. M1 and M2 are mutexes that are enabled * with priority inheritance.) Time moves forward as this timeline goes down: N1 N2 D1 | | | | | | Lock(M1) | | | | | | Lock(M2) | | | | | | Lock(M2) | | | | Lock(M1) | | (!!bug triggered!) | Daniel reported a similar situation as well, by just letting ksoftirqd run with DEADLINE (and eventually block on a mutex). Problem is that boosted entities (Priority Inheritance) use static DEADLINE parameters of the top priority waiter. However, there might be cases where top waiter could be a non-DEADLINE entity that is currently boosted by a DEADLINE entity from a different lock chain (i.e., nested priority chains involving entities of non-DEADLINE classes). In this case, top waiter static DEADLINE parameters could be null (initialized to 0 at fork()) and replenish_dl_entity() would hit a BUG(). Fix this by keeping track of the original donor and using its parameters when a task is boosted. Reported-by: Glenn Elliott <glenn@aurora.tech> Reported-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com> Link: https://lkml.kernel.org/r/20201117061432.517340-1-juri.lelli@redhat.com [Ankit: Regenerated the patch for v4.19.y] Signed-off-by: Ankit Jain <ankitja@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25watchdog: export lockup_detector_reconfigureLaurent Dufour
[ Upstream commit 7c56a8733d0a2a4be2438a7512566e5ce552fccf ] In some circumstances it may be interesting to reconfigure the watchdog from inside the kernel. On PowerPC, this may helpful before and after a LPAR migration (LPM) is initiated, because it implies some latencies, watchdog, and especially NMI watchdog is expected to be triggered during this operation. Reconfiguring the watchdog with a factor, would prevent it to happen too frequently during LPM. Rename lockup_detector_reconfigure() as __lockup_detector_reconfigure() and create a new function lockup_detector_reconfigure() calling __lockup_detector_reconfigure() under the protection of watchdog_mutex. Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> [mpe: Squash in build fix from Laurent, reported by Sachin] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220713154729.80789-3-ldufour@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25KVM: Add infrastructure and macro to mark VM as buggedSean Christopherson
commit 0b8f11737cffc1a406d1134b58687abc29d76b52 upstream Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <3a0998645c328bf0895f1290e61821b70f048549.1625186503.git.isaku.yamahata@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [SG: Adjusted context for kernel version 4.19] Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25mfd: t7l66xb: Drop platform disable callbackUwe Kleine-König
[ Upstream commit 128ac294e1b437cb8a7f2ff8ede1cde9082bddbe ] None of the in-tree instantiations of struct t7l66xb_platform_data provides a disable callback. So better don't dereference this function pointer unconditionally. As there is no user, drop it completely instead of calling it conditional. This is a preparation for making platform remove callbacks return void. Fixes: 1f192015ca5b ("mfd: driver for the T7L66XB TMIO SoC") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20220530192430.2108217-3-u.kleine-koenig@pengutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25kfifo: fix kfifo_to_user() return typeDan Carpenter
[ Upstream commit 045ed31e23aea840648c290dbde04797064960db ] The kfifo_to_user() macro is supposed to return zero for success or negative error codes. Unfortunately, there is a signedness bug so it returns unsigned int. This only affects callers which try to save the result in ssize_t and as far as I can see the only place which does that is line6_hwdep_read(). TL;DR: s/_uint/_int/. Link: https://lkml.kernel.org/r/YrVL3OJVLlNhIMFs@kili Fixes: 144ecf310eb5 ("kfifo: fix kfifo_alloc() to return a signed int value") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Stefani Seibold <stefani@seibold.net> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25USB: HCD: Fix URB giveback issue in tasklet functionWeitao Wang
commit 26c6c2f8a907c9e3a2f24990552a4d77235791e6 upstream. Usb core introduce the mechanism of giveback of URB in tasklet context to reduce hardware interrupt handling time. On some test situation(such as FIO with 4KB block size), when tasklet callback function called to giveback URB, interrupt handler add URB node to the bh->head list also. If check bh->head list again after finish all URB giveback of local_list, then it may introduce a "dynamic balance" between giveback URB and add URB to bh->head list. This tasklet callback function may not exit for a long time, which will cause other tasklet function calls to be delayed. Some real-time applications(such as KB and Mouse) will see noticeable lag. In order to prevent the tasklet function from occupying the cpu for a long time at a time, new URBS will not be added to the local_list even though the bh->head list is not empty. But also need to ensure the left URB giveback to be processed in time, so add a member high_prio for structure giveback_urb_bh to prioritize tasklet and schelule this tasklet again if bh->head list is not empty. At the same time, we are able to prioritize tasklet through structure member high_prio. So, replace the local high_prio_bh variable with this structure member in usb_hcd_giveback_urb. Fixes: 94dfd7edfd5c ("USB: HCD: support giveback of URB in tasklet context") Cc: stable <stable@kernel.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Weitao Wang <WeitaoWang-oc@zhaoxin.com> Link: https://lore.kernel.org/r/20220726074918.5114-1-WeitaoWang-oc@zhaoxin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25PCI: Add defines for normal and subtractive PCI bridgesPali Rohár
commit 904b10fb189cc15376e9bfce1ef0282e68b0b004 upstream. Add these PCI class codes to pci_ids.h: PCI_CLASS_BRIDGE_PCI_NORMAL PCI_CLASS_BRIDGE_PCI_SUBTRACTIVE Use these defines in all kernel code for describing PCI class codes for normal and subtractive PCI bridges. [bhelgaas: similar change in pci-mvebu.c] Link: https://lore.kernel.org/r/20220214114109.26809-1-pali@kernel.org Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Guenter Roeck <linux@roeck-us.net>a Cc: Naresh Kamboju <naresh.kamboju@linaro.org> [ gregkh - take only the pci_ids.h portion for stable backports ] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25add barriers to buffer_uptodate and set_buffer_uptodateMikulas Patocka
commit d4252071b97d2027d246f6a82cbee4d52f618b47 upstream. Let's have a look at this piece of code in __bread_slow: get_bh(bh); bh->b_end_io = end_buffer_read_sync; submit_bh(REQ_OP_READ, 0, bh); wait_on_buffer(bh); if (buffer_uptodate(bh)) return bh; Neither wait_on_buffer nor buffer_uptodate contain any memory barrier. Consequently, if someone calls sb_bread and then reads the buffer data, the read of buffer data may be executed before wait_on_buffer(bh) on architectures with weak memory ordering and it may return invalid data. Fix this bug by adding a memory barrier to set_buffer_uptodate and an acquire barrier to buffer_uptodate (in a similar way as folio_test_uptodate and folio_mark_uptodate). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29tty: use new tty_insert_flip_string_and_push_buffer() in pty_write()Jiri Slaby
commit a501ab75e7624d133a5a3c7ec010687c8b961d23 upstream. There is a race in pty_write(). pty_write() can be called in parallel with e.g. ioctl(TIOCSTI) or ioctl(TCXONC) which also inserts chars to the buffer. Provided, tty_flip_buffer_push() in pty_write() is called outside the lock, it can commit inconsistent tail. This can lead to out of bounds writes and other issues. See the Link below. To fix this, we have to introduce a new helper called tty_insert_flip_string_and_push_buffer(). It does both tty_insert_flip_string() and tty_flip_buffer_commit() under the port lock. It also calls queue_work(), but outside the lock. See 71a174b39f10 (pty: do tty_flip_buffer_push without port->lock in pty_write) for the reasons. Keep the helper internal-only (in drivers' tty.h). It is not intended to be used widely. Link: https://seclists.org/oss-sec/2022/q2/155 Fixes: 71a174b39f10 (pty: do tty_flip_buffer_push without port->lock in pty_write) Cc: 一只狗 <chennbnbnb@gmail.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Suggested-by: Hillf Danton <hdanton@sina.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220707082558.9250-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29tty: drop tty_schedule_flip()Jiri Slaby
commit 5db96ef23bda6c2a61a51693c85b78b52d03f654 upstream. Since commit a9c3f68f3cd8d (tty: Fix low_latency BUG) in 2014, tty_flip_buffer_push() is only a wrapper to tty_schedule_flip(). All users were converted in the previous patches, so remove tty_schedule_flip() completely while inlining its body into tty_flip_buffer_push(). One less exported function. Reviewed-by: Johan Hovold <johan@kernel.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20211122111648.30379-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-21cgroup: Use separate src/dst nodes when preloading css_sets for migrationTejun Heo
commit 07fd5b6cdf3cc30bfde8fe0f644771688be04447 upstream. Each cset (css_set) is pinned by its tasks. When we're moving tasks around across csets for a migration, we need to hold the source and destination csets to ensure that they don't go away while we're moving tasks about. This is done by linking cset->mg_preload_node on either the mgctx->preloaded_src_csets or mgctx->preloaded_dst_csets list. Using the same cset->mg_preload_node for both the src and dst lists was deemed okay as a cset can't be both the source and destination at the same time. Unfortunately, this overloading becomes problematic when multiple tasks are involved in a migration and some of them are identity noop migrations while others are actually moving across cgroups. For example, this can happen with the following sequence on cgroup1: #1> mkdir -p /sys/fs/cgroup/misc/a/b #2> echo $$ > /sys/fs/cgroup/misc/a/cgroup.procs #3> RUN_A_COMMAND_WHICH_CREATES_MULTIPLE_THREADS & #4> PID=$! #5> echo $PID > /sys/fs/cgroup/misc/a/b/tasks #6> echo $PID > /sys/fs/cgroup/misc/a/cgroup.procs the process including the group leader back into a. In this final migration, non-leader threads would be doing identity migration while the group leader is doing an actual one. After #3, let's say the whole process was in cset A, and that after #4, the leader moves to cset B. Then, during #6, the following happens: 1. cgroup_migrate_add_src() is called on B for the leader. 2. cgroup_migrate_add_src() is called on A for the other threads. 3. cgroup_migrate_prepare_dst() is called. It scans the src list. 4. It notices that B wants to migrate to A, so it tries to A to the dst list but realizes that its ->mg_preload_node is already busy. 5. and then it notices A wants to migrate to A as it's an identity migration, it culls it by list_del_init()'ing its ->mg_preload_node and putting references accordingly. 6. The rest of migration takes place with B on the src list but nothing on the dst list. This means that A isn't held while migration is in progress. If all tasks leave A before the migration finishes and the incoming task pins it, the cset will be destroyed leading to use-after-free. This is caused by overloading cset->mg_preload_node for both src and dst preload lists. We wanted to exclude the cset from the src list but ended up inadvertently excluding it from the dst list too. This patch fixes the issue by separating out cset->mg_preload_node into ->mg_src_preload_node and ->mg_dst_preload_node, so that the src and dst preloadings don't interfere with each other. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Mukesh Ojha <quic_mojha@quicinc.com> Reported-by: shisiyuan <shisiyuan19870131@gmail.com> Link: http://lkml.kernel.org/r/1654187688-27411-1-git-send-email-shisiyuan@xiaomi.com Link: https://www.spinics.net/lists/cgroups/msg33313.html Fixes: f817de98513d ("cgroup: prepare migration path for unified hierarchy") Cc: stable@vger.kernel.org # v3.16+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-12misc: rtsx_usb: use separate command and response buffersShuah Khan
commit 3776c78559853fd151be7c41e369fd076fb679d5 upstream. rtsx_usb uses same buffer for command and response. There could be a potential conflict using the same buffer for both especially if retries and timeouts are involved. Use separate command and response buffers to avoid conflicts. Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/07e3721804ff07aaab9ef5b39a5691d0718b9ade.1656642167.git.skhan@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-12misc: rtsx_usb: fix use of dma mapped buffer for usb bulk transferShuah Khan
commit eb7f8e28420372787933eec079735c35034bda7d upstream. rtsx_usb driver allocates coherent dma buffer for urb transfers. This buffer is passed to usb_bulk_msg() and usb core tries to map already mapped buffer running into a dma mapping error. xhci_hcd 0000:01:00.0: rejecting DMA map of vmalloc memory WARNING: CPU: 1 PID: 279 at include/linux/dma-mapping.h:326 usb_ hcd_map_urb_for_dma+0x7d6/0x820 ... xhci_map_urb_for_dma+0x291/0x4e0 usb_hcd_submit_urb+0x199/0x12b0 ... usb_submit_urb+0x3b8/0x9e0 usb_start_wait_urb+0xe3/0x2d0 usb_bulk_msg+0x115/0x240 rtsx_usb_transfer_data+0x185/0x1a8 [rtsx_usb] rtsx_usb_send_cmd+0xbb/0x123 [rtsx_usb] rtsx_usb_write_register+0x12c/0x143 [rtsx_usb] rtsx_usb_probe+0x226/0x4b2 [rtsx_usb] Fix it to use kmalloc() to get DMA-able memory region instead. Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/667d627d502e1ba9ff4f9b94966df3299d2d3c0d.1656642167.git.skhan@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-02kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]Naveen N. Rao
commit 3e35142ef99fe6b4fe5d834ad43ee13cca10a2dc upstream. Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") [1], binutils (v2.36+) started dropping section symbols that it thought were unused. This isn't an issue in general, but with kexec_file.c, gcc is placing kexec_arch_apply_relocations[_add] into a separate .text.unlikely section and the section symbol ".text.unlikely" is being dropped. Due to this, recordmcount is unable to find a non-weak symbol in .text.unlikely to generate a relocation record against. Address this by dropping the weak attribute from these functions. Instead, follow the existing pattern of having architectures #define the name of the function they want to override in their headers. [1] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d1bcae833b32f1 [akpm@linux-foundation.org: arch/s390/include/asm/kexec.h needs linux/module.h] Link: https://lkml.kernel.org/r/20220519091237.676736-1-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-02random: quiet urandom warning ratelimit suppression messageJason A. Donenfeld
commit c01d4d0a82b71857be7449380338bc53dde2da92 upstream. random.c ratelimits how much it warns about uninitialized urandom reads using __ratelimit(). When the RNG is finally initialized, it prints the number of missed messages due to ratelimiting. It has been this way since that functionality was introduced back in 2018. Recently, cc1e127bfa95 ("random: remove ratelimiting for in-kernel unseeded randomness") put a bit more stress on the urandom ratelimiting, which teased out a bug in the implementation. Specifically, when under pressure, __ratelimit() will print its own message and reset the count back to 0, making the final message at the end less useful. Secondly, it does so as a pr_warn(), which apparently is undesirable for people's CI. Fortunately, __ratelimit() has the RATELIMIT_MSG_ON_RELEASE flag exactly for this purpose, so we set the flag. Fixes: 4e00b339e264 ("random: rate limit unseeded randomness warnings") Cc: stable@vger.kernel.org Reported-by: Jon Hunter <jonathanh@nvidia.com> Reported-by: Ron Economos <re@w6rz.net> Tested-by: Ron Economos <re@w6rz.net> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-02vt: drop old FONT ioctlsJiri Slaby
commit ff2047fb755d4415ec3c70ac799889371151796d upstream. Drop support for these ioctls: * PIO_FONT, PIO_FONTX * GIO_FONT, GIO_FONTX * PIO_FONTRESET As was demonstrated by commit 90bfdeef83f1 (tty: make FONTX ioctl use the tty pointer they were actually passed), these ioctls are not used from userspace, as: 1) they used to be broken (set up font on current console, not the open one) and racy (before the commit above) 2) KDFONTOP ioctl is used for years instead Note that PIO_FONTRESET is defunct on most systems as VGA_CONSOLE is set on them for ages. That turns on BROKEN_GRAPHICS_PROGRAMS which makes PIO_FONTRESET just return an error. We are removing KD_FONT_FLAG_OLD here as it was used only by these removed ioctls. kd.h header exists both in kernel and uapi headers, so we can remove the kernel one completely. Everyone includeing kd.h will now automatically get the uapi one. There are now unused definitions of the ioctl numbers and "struct consolefontdesc" in kd.h, but as it is a uapi header, I am not touching these. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-8-jslaby@suse.cz Cc: guodaxing <guodaxing@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: mark bootloader randomness code as __initJason A. Donenfeld
commit 39e0f991a62ed5efabd20711a7b6e7da92603170 upstream. add_bootloader_randomness() and the variables it touches are only used during __init and not after, so mark these as __init. At the same time, unexport this, since it's only called by other __init code that's built-in. Cc: stable@vger.kernel.org Fixes: 428826f5358c ("fdt: add support for rng-seed") Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: move randomize_page() into mm where it belongsJason A. Donenfeld
commit 5ad7dd882e45d7fe432c32e896e2aaa0b21746ea upstream. randomize_page is an mm function. It is documented like one. It contains the history of one. It has the naming convention of one. It looks just like another very similar function in mm, randomize_stack_top(). And it has always been maintained and updated by mm people. There is no need for it to be in random.c. In the "which shape does not look like the other ones" test, pointing to randomize_page() is correct. So move randomize_page() into mm/util.c, right next to the similar randomize_stack_top() function. This commit contains no actual code changes. Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: use proper return types on get_random_{int,long}_wait()Jason A. Donenfeld
commit 7c3a8a1db5e03d02cc0abb3357a84b8b326dfac3 upstream. Before these were returning signed values, but the API is intended to be used with unsigned values. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: remove extern from functions in headerJason A. Donenfeld
commit 7782cfeca7d420e8bb707613d4cfb0f7ff29bb3a upstream. Accoriding to the kernel style guide, having `extern` on functions in headers is old school and deprecated, and doesn't add anything. So remove them from random.h, and tidy up the file a little bit too. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: handle latent entropy and command line from random_init()Jason A. Donenfeld
commit 2f14062bb14b0fcfcc21e6dc7d5b5c0d25966164 upstream. Currently, start_kernel() adds latent entropy and the command line to the entropy bool *after* the RNG has been initialized, deferring when it's actually used by things like stack canaries until the next time the pool is seeded. This surely is not intended. Rather than splitting up which entropy gets added where and when between start_kernel() and random_init(), just do everything in random_init(), which should eliminate these kinds of bugs in the future. While we're at it, rename the awkwardly titled "rand_initialize()" to the more standard "random_init()" nomenclature. Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25siphash: use one source of truth for siphash permutationsJason A. Donenfeld
commit e73aaae2fa9024832e1f42e30c787c7baf61d014 upstream. The SipHash family of permutations is currently used in three places: - siphash.c itself, used in the ordinary way it was intended. - random32.c, in a construction from an anonymous contributor. - random.c, as part of its fast_mix function. Each one of these places reinvents the wheel with the same C code, same rotation constants, and same symmetry-breaking constants. This commit tidies things up a bit by placing macros for the permutations and constants into siphash.h, where each of the three .c users can access them. It also leaves a note dissuading more users of them from emerging. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25timekeeping: Add raw clock fallback for random_get_entropy()Jason A. Donenfeld
commit 1366992e16bddd5e2d9a561687f367f9f802e2e4 upstream. The addition of random_get_entropy_fallback() provides access to whichever time source has the highest frequency, which is useful for gathering entropy on platforms without available cycle counters. It's not necessarily as good as being able to quickly access a cycle counter that the CPU has, but it's still something, even when it falls back to being jiffies-based. In the event that a given arch does not define get_cycles(), falling back to the get_cycles() default implementation that returns 0 is really not the best we can do. Instead, at least calling random_get_entropy_fallback() would be preferable, because that always needs to return _something_, even falling back to jiffies eventually. It's not as though random_get_entropy_fallback() is super high precision or guaranteed to be entropic, but basically anything that's not zero all the time is better than returning zero all the time. Finally, since random_get_entropy_fallback() is used during extremely early boot when randomizing freelists in mm_init(), it can be called before timekeeping has been initialized. In that case there really is nothing we can do; jiffies hasn't even started ticking yet. So just give up and return 0. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: make random_get_entropy() return an unsigned longJason A. Donenfeld
commit b0c3e796f24b588b862b61ce235d3c9417dc8983 upstream. Some implementations were returning type `unsigned long`, while others that fell back to get_cycles() were implicitly returning a `cycles_t` or an untyped constant int literal. That makes for weird and confusing code, and basically all code in the kernel already handled it like it was an `unsigned long`. I recently tried to handle it as the largest type it could be, a `cycles_t`, but doing so doesn't really help with much. Instead let's just make random_get_entropy() return an unsigned long all the time. This also matches the commonly used `arch_get_random_long()` function, so now RDRAND and RDTSC return the same sized integer, which means one can fallback to the other more gracefully. Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Theodore Ts'o <tytso@mit.edu> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: replace custom notifier chain with standard oneJason A. Donenfeld
commit 5acd35487dc911541672b3ffc322851769c32a56 upstream. We previously rolled our own randomness readiness notifier, which only has two users in the whole kernel. Replace this with a more standard atomic notifier block that serves the same purpose with less code. Also unexport the symbols, because no modules use it, only unconditional builtins. The only drawback is that it's possible for a notification handler returning the "stop" code to prevent further processing, but given that there are only two users, and that we're unexporting this anyway, that doesn't seem like a significant drawback for the simplification we receive here. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> [Jason: for stable, also backported to crypto/drbg.c, not unexporting.] Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: clear fast pool, crng, and batches in cpuhp bring upJason A. Donenfeld
commit 3191dd5a1179ef0fad5a050a1702ae98b6251e8f upstream. For the irq randomness fast pool, rather than having to use expensive atomics, which were visibly the most expensive thing in the entire irq handler, simply take care of the extreme edge case of resetting count to zero in the cpuhp online handler, just after workqueues have been reenabled. This simplifies the code a bit and lets us use vanilla variables rather than atomics, and performance should be improved. As well, very early on when the CPU comes up, while interrupts are still disabled, we clear out the per-cpu crng and its batches, so that it always starts with fresh randomness. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Sultan Alsawaf <sultan@kerneltoast.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: pull add_hwgenerator_randomness() declaration into random.hJason A. Donenfeld
commit b777c38239fec5a528e59f55b379e31b1a187524 upstream. add_hwgenerator_randomness() is a function implemented and documented inside of random.c. It is the way that hardware RNGs push data into it. Therefore, it should be declared in random.h. Otherwise sparse complains with: random.c:1137:6: warning: symbol 'add_hwgenerator_randomness' was not declared. Should it be static? The alternative would be to include hw_random.h into random.c, but that wouldn't really be good for anything except slowing down compile time. Cc: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: remove useless header commentJason A. Donenfeld
commit 6071a6c0fba2d747742cadcbb3ba26ed756ed73b upstream. This really adds nothing at all useful. Cc: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: use hash function for crng_slow_load()Jason A. Donenfeld
commit 66e4c2b9541503d721e936cc3898c9f25f4591ff upstream. Since we have a hash function that's really fast, and the goal of crng_slow_load() is reportedly to "touch all of the crng's state", we can just hash the old state together with the new state and call it a day. This way we dont need to reason about another LFSR or worry about various attacks there. This code is only ever used at early boot and then never again. Cc: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: remove unused irq_flags argument from add_interrupt_randomness()Sebastian Andrzej Siewior
commit 703f7066f40599c290babdb79dd61319264987e9 upstream. Since commit ee3e00e9e7101 ("random: use registers from interrupted code for CPU's w/o a cycle counter") the irq_flags argument is no longer used. Remove unused irq_flags. Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Liu <wei.liu@kernel.org> Cc: linux-hyperv@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: add arch_get_random_*long_early()Mark Rutland
commit 253d3194c2b58152fe830fd27c2fd83ebc6fe5ee upstream. Some architectures (e.g. arm64) can have heterogeneous CPUs, and the boot CPU may be able to provide entropy while secondary CPUs cannot. On such systems, arch_get_random_long() and arch_get_random_seed_long() will fail unless support for RNG instructions has been detected on all CPUs. This prevents the boot CPU from being able to provide (potentially) trusted entropy when seeding the primary CRNG. To make it possible to seed the primary CRNG from the boot CPU without adversely affecting the runtime versions of arch_get_random_long() and arch_get_random_seed_long(), this patch adds new early versions of the functions used when initializing the primary CRNG. Default implementations are provided atop of the existing arch_get_random_long() and arch_get_random_seed_long() so that only architectures with such constraints need to provide the new helpers. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Mark Brown <broonie@kernel.org> Cc: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20200210130015.17664-3-mark.rutland@arm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25linux/random.h: Mark CONFIG_ARCH_RANDOM functions __must_checkRichard Henderson
commit 904caa6413c87aacbf7d0682da617c39ca18cf1a upstream. We must not use the pointer output without validating the success of the random read. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20200110145422.49141-7-broonie@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25linux/random.h: Use false with boolRichard Henderson
commit 66f5ae899ada79c0e9a3d8d954f93a72344cd350 upstream. Keep the generic fallback versions in sync with the other architecture specific implementations and use the proper name for false. Suggested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20200110145422.49141-6-broonie@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25linux/random.h: Remove arch_has_random, arch_has_random_seedRichard Henderson
commit 647f50d5d9d933b644b29c54f13ac52af1b1774d upstream. The arm64 version of archrandom.h will need to be able to test for support and read the random number without preemption, so a separate query predicate is not practical. Since this part of the generic interface is unused, remove it. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20200110145422.49141-5-broonie@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25fdt: add support for rng-seedHsin-Yi Wang
commit 428826f5358c922dc378830a1717b682c0823160 upstream. Introducing a chosen node, rng-seed, which is an entropy that can be passed to kernel called very early to increase initial device randomness. Bootloader should provide this entropy and the value is read from /chosen/rng-seed in DT. Obtain of_fdt_crc32 for CRC check after early_init_dt_scan_nodes(), since early_init_dt_scan_chosen() would modify fdt to erase rng-seed. Add a new interface add_bootloader_randomness() for rng-seed use case. Depends on whether the seed is trustworthy, rng seed would be passed to add_hwgenerator_randomness(). Otherwise it would be passed to add_device_randomness(). Decision is controlled by kernel config RANDOM_TRUST_BOOTLOADER. Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Theodore Ts'o <tytso@mit.edu> # drivers/char/random.c Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25latent_entropy: avoid build error when plugin cflags are not setVasily Gorbik
commit 7e756f423af808b6571fed3144747db2ef7fa1c5 upstream. Some architectures set up CFLAGS for linux decompressor phase from scratch and do not include GCC_PLUGINS_CFLAGS. Since "latent_entropy" variable declaration is generated by the plugin code itself including linux/random.h in decompressor code then would cause a build error. E.g. on s390: In file included from ./include/linux/net.h:22, from ./include/linux/skbuff.h:29, from ./include/linux/if_ether.h:23, from ./arch/s390/include/asm/diag.h:12, from arch/s390/boot/startup.c:8: ./include/linux/random.h: In function 'add_latent_entropy': ./include/linux/random.h:26:39: error: 'latent_entropy' undeclared (first use in this function); did you mean 'add_latent_entropy'? 26 | add_device_randomness((const void *)&latent_entropy, | ^~~~~~~~~~~~~~ | add_latent_entropy ./include/linux/random.h:26:39: note: each undeclared identifier is reported only once for each function it appears in The build error is triggered by commit a80313ff91ab ("s390/kernel: introduce .dma sections") which made it into 5.2 merge window. To address that avoid using CONFIG_GCC_PLUGIN_LATENT_ENTROPY in favour of LATENT_ENTROPY_PLUGIN definition which is defined as a part of gcc plugins cflags and hence reflect more accurately when gcc plugin is active. Besides that it is also used for similar purpose in linux/compiler-gcc.h for latent_entropy attribute definition. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: move rand_initialize() earlierKees Cook
commit d55535232c3dbde9a523a9d10d68670f5fe5dec3 upstream. Right now rand_initialize() is run as an early_initcall(), but it only depends on timekeeping_init() (for mixing ktime_get_real() into the pools). However, the call to boot_init_stack_canary() for stack canary initialization runs earlier, which triggers a warning at boot: random: get_random_bytes called from start_kernel+0x357/0x548 with crng_init=0 Instead, this moves rand_initialize() to after timekeeping_init(), and moves canary initialization here as well. Note that this warning may still remain for machines that do not have UEFI RNG support (which initializes the RNG pools during setup_arch()), or for x86 machines without RDRAND (or booting without "random.trust=on" or CONFIG_RANDOM_TRUST_CPU=y). Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-16x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale DataPawan Gupta
commit 8d50cdf8b8341770bc6367bce40c0c1bb0e1d5b3 upstream Add the sysfs reporting file for Processor MMIO Stale Data vulnerability. It exposes the vulnerability and mitigation state similar to the existing files for the other hardware vulnerabilities. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-16cpu/speculation: Add prototype for cpu_show_srbds()Guenter Roeck
commit 2accfa69050c2a0d6fc6106f609208b3e9622b26 upstream. 0-day is not happy that there is no prototype for cpu_show_srbds(): drivers/base/cpu.c:565:16: error: no previous prototype for 'cpu_show_srbds' Fixes: 7e5b3c267d25 ("x86/speculation: Add Special Register Buffer Data Sampling (SRBDS) mitigation") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200617141410.93338-1-linux@roeck-us.net Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14mtd: cfi_cmdset_0002: Use chip_ready() for write on S29GL064NTokunori Ikegami
commit 0a8e98305f63deaf0a799d5cf5532cc83af035d1 upstream. Since commit dfeae1073583("mtd: cfi_cmdset_0002: Change write buffer to check correct value") buffered writes fail on S29GL064N. This is because, on S29GL064N, reads return 0xFF at the end of DQ polling for write completion, where as, chip_good() check expects actual data written to the last location to be returned post DQ polling completion. Fix is to revert to using chip_good() for S29GL064N which only checks for DQ lines to settle down to determine write completion. Link: https://lore.kernel.org/r/b687c259-6413-26c9-d4c9-b3afa69ea124@pengutronix.de/ Fixes: dfeae1073583("mtd: cfi_cmdset_0002: Change write buffer to check correct value") Cc: stable@vger.kernel.org Signed-off-by: Tokunori Ikegami <ikegami.t@gmail.com> Acked-by: Vignesh Raghavendra <vigneshr@ti.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20220323170458.5608-3-ikegami.t@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14nodemask: Fix return values to be unsignedKees Cook
[ Upstream commit 0dfe54071d7c828a02917b595456bfde1afdddc9 ] The nodemask routines had mixed return values that provided potentially signed return values that could never happen. This was leading to the compiler getting confusing about the range of possible return values (it was thinking things could be negative where they could not be). Fix all the nodemask routines that should be returning unsigned (or bool) values. Silences: mm/swapfile.c: In function ‘setup_swap_info’: mm/swapfile.c:2291:47: error: array subscript -1 is below array bounds of ‘struct plist_node[]’ [-Werror=array-bounds] 2291 | p->avail_lists[i].prio = 1; | ~~~~~~~~~~~~~~^~~ In file included from mm/swapfile.c:16: ./include/linux/swap.h:292:27: note: while referencing ‘avail_lists’ 292 | struct plist_node avail_lists[]; /* | ^~~~~~~~~~~ Reported-by: Christophe de Dinechin <dinechin@redhat.com> Link: https://lore.kernel.org/lkml/20220414150855.2407137-3-dinechin@redhat.com/ Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Yury Norov <yury.norov@gmail.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14nodemask.h: fix compilation error with GCC12Christophe de Dinechin
commit 37462a920392cb86541650a6f4121155f11f1199 upstream. With gcc version 12.0.1 20220401 (Red Hat 12.0.1-0), building with defconfig results in the following compilation error: | CC mm/swapfile.o | mm/swapfile.c: In function `setup_swap_info': | mm/swapfile.c:2291:47: error: array subscript -1 is below array bounds | of `struct plist_node[]' [-Werror=array-bounds] | 2291 | p->avail_lists[i].prio = 1; | | ~~~~~~~~~~~~~~^~~ | In file included from mm/swapfile.c:16: | ./include/linux/swap.h:292:27: note: while referencing `avail_lists' | 292 | struct plist_node avail_lists[]; /* | | ^~~~~~~~~~~ This is due to the compiler detecting that the mask in node_states[__state] could theoretically be zero, which would lead to first_node() returning -1 through find_first_bit. I believe that the warning/error is legitimate. I first tried adding a test to check that the node mask is not emtpy, since a similar test exists in the case where MAX_NUMNODES == 1. However, adding the if statement causes other warnings to appear in for_each_cpu_node_but, because it introduces a dangling else ambiguity. And unfortunately, GCC is not smart enough to detect that the added test makes the case where (node) == -1 impossible, so it still complains with the same message. This is why I settled on replacing that with a harmless, but relatively useless (node) >= 0 test. Based on the warning for the dangling else, I also decided to fix the case where MAX_NUMNODES == 1 by moving the condition inside the for loop. It will still only be tested once. This ensures that the meaning of an else following for_each_node_mask or derivatives would not silently have a different meaning depending on the configuration. Link: https://lkml.kernel.org/r/20220414150855.2407137-3-dinechin@redhat.com Signed-off-by: Christophe de Dinechin <christophe@dinechin.org> Signed-off-by: Christophe de Dinechin <dinechin@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Ben Segall <bsegall@google.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Zhen Lei <thunder.leizhen@huawei.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>