user/sven/linux.git/lib, branch v5.1.17

lib/mpi: Fix karactx leak in mpi_powm

2019-07-10T07:52:29Z

commit c8ea9fce2baf7b643384f36f29e4194fa40d33a6 upstream. Sometimes mpi_powm will leak karactx because a memory allocation failure causes a bail-out that skips the freeing of karactx. This patch moves the freeing of karactx to the end of the function like everything else so that it can't be skipped. Reported-by: syzbot+f7baccc38dcc1e094e77@syzkaller.appspotmail.com Fixes: cdec9cb5167a ("crypto: GnuPG based MPI lib - source files...") Cc: Signed-off-by: Herbert Xu Reviewed-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

idr: Fix idr_get_next race with idr_remove

2019-07-10T07:52:21Z

commit 5c089fd0c73411f2170ab795c9ffc16718c7d007 upstream. If the entry is deleted from the IDR between the call to radix_tree_iter_find() and rcu_dereference_raw(), idr_get_next() will return NULL, which will end the iteration prematurely. We should instead continue to the next entry in the IDR. This only happens if the iteration is protected by the RCU lock. Most IDR users use a spinlock or semaphore to exclude simultaneous modifications. It was noticed once the PID allocator was converted to use the IDR, as it uses the RCU lock, but there may be other users elsewhere in the kernel. We can't use the normal pattern of calling radix_tree_deref_retry() (which catches both a retry entry in a leaf node and a node entry in the root) as the IDR supports storing entries which are unaligned, which will trigger an infinite loop if they are encountered. Instead, we have to explicitly check whether the entry is a retry entry. Fixes: 0a835c4f090a ("Reimplement IDR and IDA using the radix tree") Reported-by: Brendan Gregg Tested-by: Brendan Gregg Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Greg Kroah-Hartman

mm: fix page cache convergence regression

2019-07-03T11:13:39Z

commit 7b785645e8f13e17cbce492708cf6e7039d32e46 upstream. Since a28334862993 ("page cache: Finish XArray conversion"), on most major Linux distributions, the page cache doesn't correctly transition when the hot data set is changing, and leaves the new pages thrashing indefinitely instead of kicking out the cold ones. On a freshly booted, freshly ssh'd into virtual machine with 1G RAM running stock Arch Linux: [root@ham ~]# ./reclaimtest.sh + dd of=workingset-a bs=1M count=0 seek=600 + cat workingset-a + cat workingset-a + cat workingset-a + cat workingset-a + cat workingset-a + cat workingset-a + cat workingset-a + cat workingset-a + ./mincore workingset-a 153600/153600 workingset-a + dd of=workingset-b bs=1M count=0 seek=600 + cat workingset-b + cat workingset-b + cat workingset-b + cat workingset-b + ./mincore workingset-a workingset-b 104029/153600 workingset-a 120086/153600 workingset-b + cat workingset-b + cat workingset-b + cat workingset-b + cat workingset-b + ./mincore workingset-a workingset-b 104029/153600 workingset-a 120268/153600 workingset-b workingset-b is a 600M file on a 1G host that is otherwise entirely idle. No matter how often it's being accessed, it won't get cached. While investigating, I noticed that the non-resident information gets aggressively reclaimed - /proc/vmstat::workingset_nodereclaim. This is a problem because a workingset transition like this relies on the non-resident information tracked in the page cache tree of evicted file ranges: when the cache faults are refaults of recently evicted cache, we challenge the existing active set, and that allows a new workingset to establish itself. Tracing the shrinker that maintains this memory revealed that all page cache tree nodes were allocated to the root cgroup. This is a problem, because 1) the shrinker sizes the amount of non-resident information it keeps to the size of the cgroup's other memory and 2) on most major Linux distributions, only kernel threads live in the root cgroup and everything else gets put into services or session groups: [root@ham ~]# cat /proc/self/cgroup 0::/user.slice/user-0.slice/session-c1.scope As a result, we basically maintain no non-resident information for the workloads running on the system, thus breaking the caching algorithm. Looking through the code, I found the culprit in the above-mentioned patch: when switching from the radix tree to xarray, it dropped the __GFP_ACCOUNT flag from the tree node allocations - the flag that makes sure the allocated memory gets charged to and tracked by the cgroup of the calling process - in this case, the one doing the fault. To fix this, allow xarray users to specify per-tree flag that makes xarray allocate nodes using __GFP_ACCOUNT. Then restore the page cache tree annotation to request such cgroup tracking for the cache nodes. With this patch applied, the page cache correctly converges on new workingsets again after just a few iterations: [root@ham ~]# ./reclaimtest.sh + dd of=workingset-a bs=1M count=0 seek=600 + cat workingset-a + cat workingset-a + cat workingset-a + cat workingset-a + cat workingset-a + cat workingset-a + cat workingset-a + cat workingset-a + ./mincore workingset-a 153600/153600 workingset-a + dd of=workingset-b bs=1M count=0 seek=600 + cat workingset-b + ./mincore workingset-a workingset-b 124607/153600 workingset-a 87876/153600 workingset-b + cat workingset-b + ./mincore workingset-a workingset-b 81313/153600 workingset-a 133321/153600 workingset-b + cat workingset-b + ./mincore workingset-a workingset-b 63036/153600 workingset-a 153600/153600 workingset-b Cc: stable@vger.kernel.org # 4.20+ Signed-off-by: Johannes Weiner Reviewed-by: Shakeel Butt Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Greg Kroah-Hartman

test_firmware: Use correct snprintf() limit

2019-06-11T10:19:19Z

commit bd17cc5a20ae9aaa3ed775f360b75ff93cd66a1d upstream. The limit here is supposed to be how much of the page is left, but it's just using PAGE_SIZE as the limit. The other thing to remember is that snprintf() returns the number of bytes which would have been copied if we had had enough room. So that means that if we run out of space then this code would end up passing a negative value as the limit and the kernel would print an error message. I have change the code to use scnprintf() which returns the number of bytes that were successfully printed (not counting the NUL terminator). Fixes: c92316bf8e94 ("test_firmware: add batched firmware tests") Signed-off-by: Dan Carpenter Cc: stable Signed-off-by: Greg Kroah-Hartman

kobject: Don't trigger kobject_uevent(KOBJ_REMOVE) twice.

2019-05-31T13:43:44Z

[ Upstream commit c03a0fd0b609e2f5c669c2b7f27c8e1928e9196e ] syzbot is hitting use-after-free bug in uinput module [1]. This is because kobject_uevent(KOBJ_REMOVE) is called again due to commit 0f4dafc0563c6c49 ("Kobject: auto-cleanup on final unref") after memory allocation fault injection made kobject_uevent(KOBJ_REMOVE) from device_del() from input_unregister_device() fail, while uinput_destroy_device() is expecting that kobject_uevent(KOBJ_REMOVE) is not called after device_del() from input_unregister_device() completed. That commit intended to catch cases where nobody even attempted to send "remove" uevents. But there is no guarantee that an event will ultimately be sent. We are at the point of no return as far as the rest of the kernel is concerned; there are no repeats or do-overs. Also, it is not clear whether some subsystem depends on that commit. If no subsystem depends on that commit, it will be better to remove the state_{add,remove}_uevent_sent logic. But we don't want to risk a regression (in a patch which will be backported) by trying to remove that logic. Therefore, as a first step, let's avoid the use-after-free bug by making sure that kobject_uevent(KOBJ_REMOVE) won't be triggered twice. [1] https://syzkaller.appspot.com/bug?id=8b17c134fe938bbddd75a45afaa9e68af43a362d Reported-by: syzbot Analyzed-by: Dmitry Torokhov Fixes: 0f4dafc0563c6c49 ("Kobject: auto-cleanup on final unref") Cc: Kay Sievers Signed-off-by: Tetsuo Handa Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

mm/uaccess: Use 'unsigned long' to placate UBSAN warnings on older GCC versions

2019-05-31T13:43:25Z

[ Upstream commit 29da93fea3ea39ab9b12270cc6be1b70ef201c9e ] Randy reported objtool triggered on his (GCC-7.4) build: lib/strncpy_from_user.o: warning: objtool: strncpy_from_user()+0x315: call to __ubsan_handle_add_overflow() with UACCESS enabled lib/strnlen_user.o: warning: objtool: strnlen_user()+0x337: call to __ubsan_handle_sub_overflow() with UACCESS enabled This is due to UBSAN generating signed-overflow-UB warnings where it should not. Prior to GCC-8 UBSAN ignored -fwrapv (which the kernel uses through -fno-strict-overflow). Make the functions use 'unsigned long' throughout. Reported-by: Randy Dunlap Signed-off-by: Peter Zijlstra (Intel) Acked-by: Randy Dunlap # build-tested Acked-by: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: luto@kernel.org Link: http://lkml.kernel.org/r/20190424072208.754094071@infradead.org Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

sbitmap: fix improper use of smp_mb__before_atomic()

2019-05-31T13:43:09Z

commit a0934fd2b1208458e55fc4b48f55889809fce666 upstream. This barrier only applies to the read-modify-write operations; in particular, it does not apply to the atomic_set() primitive. Replace the barrier with an smp_mb(). Fixes: 6c0ca7ae292ad ("sbitmap: fix wakeup hang after sbq resize") Cc: stable@vger.kernel.org Reported-by: "Paul E. McKenney" Reported-by: Peter Zijlstra Signed-off-by: Andrea Parri Reviewed-by: Ming Lei Cc: Jens Axboe Cc: Omar Sandoval Cc: Ming Lei Cc: linux-block@vger.kernel.org Cc: "Paul E. McKenney" Cc: Peter Zijlstra Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

ubsan: Fix nasty -Wbuiltin-declaration-mismatch GCC-9 warnings

2019-05-11T05:49:53Z

commit f0996bc2978e02d2ea898101462b960f6119b18f upstream. Building lib/ubsan.c with gcc-9 results in a ton of nasty warnings like this one: lib/ubsan.c warning: conflicting types for built-in function ‘__ubsan_handle_negate_overflow’; expected ‘void(void *, void *)’ [-Wbuiltin-declaration-mismatch] The kernel's declarations of __ubsan_handle_*() often uses 'unsigned long' types in parameters while GCC these parameters as 'void *' types, hence the mismatch. Fix this by using 'void *' to match GCC's declarations. Reported-by: Linus Torvalds Signed-off-by: Andrey Ryabinin Fixes: c6d308534aef ("UBSAN: run-time undefined behavior sanity checker") Cc: Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-05-05T21:26:11Z

Pull x86 fix from Ingo Molnar: "Disable function tracing during early SME setup to fix a boot crash on SME-enabled kernels running distro kernels (some of which have function tracing enabled)" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/mem_encrypt: Disable all instrumentation for early SME setup

x86/mm/mem_encrypt: Disable all instrumentation for early SME setup

2019-04-30T15:59:08Z

Enablement of AMD's Secure Memory Encryption feature is determined very early after start_kernel() is entered. Part of this procedure involves scanning the command line for the parameter 'mem_encrypt'. To determine intended state, the function sme_enable() uses library functions cmdline_find_option() and strncmp(). Their use occurs early enough such that it cannot be assumed that any instrumentation subsystem is initialized. For example, making calls to a KASAN-instrumented function before KASAN is set up will result in the use of uninitialized memory and a boot failure. When AMD's SME support is enabled, conditionally disable instrumentation of these dependent functions in lib/string.c and arch/x86/lib/cmdline.c. [ bp: Get rid of intermediary nostackp var and cleanup whitespace. ] Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption") Reported-by: Li RongQing Signed-off-by: Gary R Hook Signed-off-by: Borislav Petkov Cc: Alexander Shishkin Cc: Andrew Morton Cc: Andy Shevchenko Cc: Boris Brezillon Cc: Coly Li Cc: "dave.hansen@linux.intel.com" Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Kees Cook Cc: Kent Overstreet Cc: "luto@kernel.org" Cc: Masahiro Yamada Cc: Matthew Wilcox Cc: "mingo@redhat.com" Cc: "peterz@infradead.org" Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/155657657552.7116.18363762932464011367.stgit@sosrh3.amd.com