user/sven/linux.git/kernel, branch v5.15.141

lockdep: Fix block chain corruption

2023-12-03T06:31:23Z

[ Upstream commit bca4104b00fec60be330cd32818dd5c70db3d469 ] Kent reported an occasional KASAN splat in lockdep. Mark then noted: > I suspect the dodgy access is to chain_block_buckets[-1], which hits the last 4 > bytes of the redzone and gets (incorrectly/misleadingly) attributed to > nr_large_chain_blocks. That would mean @size == 0, at which point size_to_bucket() returns -1 and the above happens. alloc_chain_hlocks() has 'size - req', for the first with the precondition 'size >= rq', which allows the 0. This code is trying to split a block, del_chain_block() takes what we need, and add_chain_block() puts back the remainder, except in the above case the remainder is 0 sized and things go sideways. Fixes: 810507fe6fd5 ("locking/lockdep: Reuse freed chain_hlocks entries") Reported-by: Kent Overstreet Signed-off-by: Peter Zijlstra (Intel) Tested-by: Kent Overstreet Link: https://lkml.kernel.org/r/20231121114126.GH8262@noisy.programming.kicks-ass.net Signed-off-by: Sasha Levin

tracing: Have trace_event_file have ref counters

2023-11-28T16:56:36Z

commit bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4 upstream. The following can crash the kernel: # cd /sys/kernel/tracing # echo 'p:sched schedule' > kprobe_events # exec 5>>events/kprobes/sched/enable # > kprobe_events # exec 5>&- The above commands: 1. Change directory to the tracefs directory 2. Create a kprobe event (doesn't matter what one) 3. Open bash file descriptor 5 on the enable file of the kprobe event 4. Delete the kprobe event (removes the files too) 5. Close the bash file descriptor 5 The above causes a crash! BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 877 Comm: bash Not tainted 6.5.0-rc4-test-00008-g2c6b6b1029d4-dirty #186 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:tracing_release_file_tr+0xc/0x50 What happens here is that the kprobe event creates a trace_event_file "file" descriptor that represents the file in tracefs to the event. It maintains state of the event (is it enabled for the given instance?). Opening the "enable" file gets a reference to the event "file" descriptor via the open file descriptor. When the kprobe event is deleted, the file is also deleted from the tracefs system which also frees the event "file" descriptor. But as the tracefs file is still opened by user space, it will not be totally removed until the final dput() is called on it. But this is not true with the event "file" descriptor that is already freed. If the user does a write to or simply closes the file descriptor it will reference the event "file" descriptor that was just freed, causing a use-after-free bug. To solve this, add a ref count to the event "file" descriptor as well as a new flag called "FREED". The "file" will not be freed until the last reference is released. But the FREE flag will be set when the event is removed to prevent any more modifications to that event from happening, even if there's still a reference to the event "file" descriptor. Link: https://lore.kernel.org/linux-trace-kernel/20231031000031.1e705592@gandalf.local.home/ Link: https://lore.kernel.org/linux-trace-kernel/20231031122453.7a48b923@gandalf.local.home Cc: stable@vger.kernel.org Cc: Mark Rutland Fixes: f5ca233e2e66d ("tracing: Increase trace array ref count on enable and filter files") Reported-by: Beau Belgrave Tested-by: Beau Belgrave Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

tracing: Have the user copy of synthetic event address use correct context

2023-11-28T16:56:31Z

commit 4f7969bcd6d33042d62e249b41b5578161e4c868 upstream. A synthetic event is created by the synthetic event interface that can read both user or kernel address memory. In reality, it reads any arbitrary memory location from within the kernel. If the address space is in USER (where CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE is set) then it uses strncpy_from_user_nofault() to copy strings otherwise it uses strncpy_from_kernel_nofault(). But since both functions use the same variable there's no annotation to what that variable is (ie. __user). This makes sparse complain. Quiet sparse by typecasting the strncpy_from_user_nofault() variable to a __user pointer. Link: https://lore.kernel.org/linux-trace-kernel/20231031151033.73c42e23@gandalf.local.home Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mark Rutland Fixes: 0934ae9977c2 ("tracing: Fix reading strings from synthetic events"); Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202311010013.fm8WTxa5-lkp@intel.com/ Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

kernel/reboot: emergency_restart: Set correct system_state

2023-11-28T16:56:31Z

commit 60466c067927abbcaff299845abd4b7069963139 upstream. As the emergency restart does not call kernel_restart_prepare(), the system_state stays in SYSTEM_RUNNING. Since bae1d3a05a8b, this hinders i2c_in_atomic_xfer_mode() from becoming active, and therefore might lead to avoidable warnings in the restart handlers, e.g.: [ 12.667612] WARNING: CPU: 1 PID: 1 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x33c/0x6b0 [ 12.676926] Voluntary context switch within RCU read-side critical section! ... [ 12.742376] schedule_timeout from wait_for_completion_timeout+0x90/0x114 [ 12.749179] wait_for_completion_timeout from tegra_i2c_wait_completion+0x40/0x70 ... [ 12.994527] atomic_notifier_call_chain from machine_restart+0x34/0x58 [ 13.001050] machine_restart from panic+0x2a8/0x32c Avoid these by setting the correct system_state. Fixes: bae1d3a05a8b ("i2c: core: remove use of in_atomic()") Cc: stable@vger.kernel.org # v5.2+ Reviewed-by: Dmitry Osipenko Tested-by: Nishanth Menon Signed-off-by: Benjamin Bara Link: https://lore.kernel.org/r/20230327-tegra-pmic-reboot-v7-1-18699d5dcd76@skidata.com Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman

genirq/generic_chip: Make irq_remove_generic_chip() irqdomain aware

2023-11-28T16:56:30Z

commit 5e7afb2eb7b2a7c81e9f608cbdf74a07606fd1b5 upstream. irq_remove_generic_chip() calculates the Linux interrupt number for removing the handler and interrupt chip based on gc::irq_base as a linear function of the bit positions of set bits in the @msk argument. When the generic chip is present in an irq domain, i.e. created with a call to irq_alloc_domain_generic_chips(), gc::irq_base contains not the base Linux interrupt number. It contains the base hardware interrupt for this chip. It is set to 0 for the first chip in the domain, 0 + N for the next chip, where $N is the number of hardware interrupts per chip. That means the Linux interrupt number cannot be calculated based on gc::irq_base for irqdomain based chips without a domain map lookup, which is currently missing. Rework the code to take the irqdomain case into account and calculate the Linux interrupt number by a irqdomain lookup of the domain specific hardware interrupt number. [ tglx: Massage changelog. Reshuffle the logic and add a proper comment. ] Fixes: cfefd21e693d ("genirq: Add chip suspend and resume callbacks") Signed-off-by: Herve Codina Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20231024150335.322282-1-herve.codina@bootlin.com Signed-off-by: Greg Kroah-Hartman

rcu: kmemleak: Ignore kmemleak false positives when RCU-freeing objects

2023-11-28T16:56:29Z

commit 5f98fd034ca6fd1ab8c91a3488968a0e9caaabf6 upstream. Since the actual slab freeing is deferred when calling kvfree_rcu(), so is the kmemleak_free() callback informing kmemleak of the object deletion. From the perspective of the kvfree_rcu() caller, the object is freed and it may remove any references to it. Since kmemleak does not scan RCU internal data storing the pointer, it will report such objects as leaks during the grace period. Tell kmemleak to ignore such objects on the kvfree_call_rcu() path. Note that the tiny RCU implementation does not have such issue since the objects can be tracked from the rcu_ctrlblk structure. Signed-off-by: Catalin Marinas Reported-by: Christoph Paasch Closes: https://lore.kernel.org/all/F903A825-F05F-4B77-A2B5-7356282FBA2C@apple.com/ Cc: Tested-by: Christoph Paasch Reviewed-by: Paul E. McKenney Signed-off-by: Joel Fernandes (Google) Signed-off-by: Frederic Weisbecker Signed-off-by: Greg Kroah-Hartman

PM: hibernate: Clean up sync_read handling in snapshot_write_next()

2023-11-28T16:56:29Z

commit d08970df1980476f27936e24d452550f3e9e92e1 upstream. In snapshot_write_next(), sync_read is set and unset in three different spots unnecessiarly. As a result there is a subtle bug where the first page after the meta data has been loaded unconditionally sets sync_read to 0. If this first PFN was actually a highmem page, then the returned buffer will be the global "buffer," and the page needs to be loaded synchronously. That is, I'm not sure we can always assume the following to be safe: handle->buffer = get_buffer(&orig_bm, &ca); handle->sync_read = 0; Because get_buffer() can call get_highmem_page_buffer() which can return 'buffer'. The easiest way to address this is just set sync_read before snapshot_write_next() returns if handle->buffer == buffer. Signed-off-by: Brian Geffon Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem") Cc: All applicable [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM: hibernate: Use __get_safe_page() rather than touching the list

2023-11-28T16:56:29Z

commit f0c7183008b41e92fa676406d87f18773724b48b upstream. We found at least one situation where the safe pages list was empty and get_buffer() would gladly try to use a NULL pointer. Signed-off-by: Brian Geffon Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem") Cc: All applicable Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

rcu/tree: Defer setting of jiffies during stall reset

2023-11-28T16:56:29Z

commit b96e7a5fa0ba9cda32888e04f8f4bac42d49a7f8 upstream. There are instances where rcu_cpu_stall_reset() is called when jiffies did not get a chance to update for a long time. Before jiffies is updated, the CPU stall detector can go off triggering false-positives where a just-started grace period appears to be ages old. In the past, we disabled stall detection in rcu_cpu_stall_reset() however this got changed [1]. This is resulting in false-positives in KGDB usecase [2]. Fix this by deferring the update of jiffies to the third run of the FQS loop. This is more robust, as, even if rcu_cpu_stall_reset() is called just before jiffies is read, we would end up pushing out the jiffies read by 3 more FQS loops. Meanwhile the CPU stall detection will be delayed and we will not get any false positives. [1] https://lore.kernel.org/all/20210521155624.174524-2-senozhatsky@chromium.org/ [2] https://lore.kernel.org/all/20230814020045.51950-2-chenhuacai@loongson.cn/ Tested with rcutorture.cpu_stall option as well to verify stall behavior with/without patch. Tested-by: Huacai Chen Reported-by: Binbin Zhou Closes: https://lore.kernel.org/all/20230814020045.51950-2-chenhuacai@loongson.cn/ Suggested-by: Paul McKenney Cc: Sergey Senozhatsky Cc: Thomas Gleixner Cc: stable@vger.kernel.org Fixes: a80be428fbc1 ("rcu: Do not disable GP stall detection in rcu_cpu_stall_reset()") Signed-off-by: Joel Fernandes (Google) Signed-off-by: Paul E. McKenney Signed-off-by: Frederic Weisbecker Signed-off-by: Greg Kroah-Hartman

watchdog: move softlockup_panic back to early_param

2023-11-28T16:56:28Z

commit 8b793bcda61f6c3ed4f5b2ded7530ef6749580cb upstream. Setting softlockup_panic from do_sysctl_args() causes it to take effect later in boot. The lockup detector is enabled before SMP is brought online, but do_sysctl_args runs afterwards. If a user wants to set softlockup_panic on boot and have it trigger should a softlockup occur during onlining of the non-boot processors, they could do this prior to commit f117955a2255 ("kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases"). However, after this commit the value of softlockup_panic is set too late to be of help for this type of problem. Restore the prior behavior. Signed-off-by: Krister Johansen Cc: stable@vger.kernel.org Fixes: f117955a2255 ("kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases") Signed-off-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman