No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Breno Leitao c7b6ea0ede mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock
[ Upstream commit 47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2 ]

When netpoll is enabled, calling pr_warn_once() while holding
kmemleak_lock in mem_pool_alloc() can cause a deadlock due to lock
inversion with the netconsole subsystem.  This occurs because
pr_warn_once() may trigger netpoll, which eventually leads to
__alloc_skb() and back into kmemleak code, attempting to reacquire
kmemleak_lock.

This is the path for the deadlock.

mem_pool_alloc()
  -> raw_spin_lock_irqsave(&kmemleak_lock, flags);
      -> pr_warn_once()
          -> netconsole subsystem
	     -> netpoll
	         -> __alloc_skb
		   -> __create_object
		     -> raw_spin_lock_irqsave(&kmemleak_lock, flags);

Fix this by setting a flag and issuing the pr_warn_once() after
kmemleak_lock is released.

Link: https://lkml.kernel.org/r/20250731-kmemleak_lock-v1-1-728fd470198f@debian.org
Fixes: c566586818 ("mm: kmemleak: use the memory pool for early allocations")
Signed-off-by: Breno Leitao <leitao@debian.org>
Reported-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:21:34 +02:00
arch x86/fpu: Delay instruction pointer fixup until after warning 2025-08-28 16:21:34 +02:00
block
certs
crypto crypto: algif_hash - fix double free in hash_accept 2025-06-04 14:32:35 +02:00
Documentation Documentation: ACPI: Fix parent device references 2025-08-28 16:21:23 +02:00
drivers pmdomain: governor: Consider CPU latency tolerance from pm_domain_cpu_gov 2025-08-28 16:21:34 +02:00
fs nfsd: handle get_client_locked() failure in nfsd4_setclientid_confirm() 2025-08-28 16:21:34 +02:00
include net: usbnet: Avoid potential RCU stall on LINK_CHANGE event 2025-08-28 16:21:33 +02:00
init bpfilter: match bit size of bpfilter_umh to that of the kernel 2025-07-17 18:24:51 +02:00
ipc ipc: fix to protect IPCS lookups using RCU 2025-06-27 11:02:52 +01:00
kernel tracing: Add down_write(trace_event_sem) when adding trace event 2025-08-28 16:21:34 +02:00
lib lib: test_objagg: Set error message in check_expect_hints_stats() 2025-07-17 18:24:56 +02:00
LICENSES
mm mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock 2025-08-28 16:21:34 +02:00
net net: ncsi: Fix buffer overflow in fetching version id 2025-08-28 16:21:27 +02:00
samples samples: mei: Fix building on musl libc 2025-08-28 16:21:19 +02:00
scripts kbuild: Add KBUILD_CPPFLAGS to as-option invocation 2025-08-28 16:21:33 +02:00
security securityfs: don't pin dentries twice, once is enough... 2025-08-28 16:21:24 +02:00
sound ALSA: scarlett2: Add retry on -EPROTO from scarlett2_usb_tx() 2025-08-28 16:21:34 +02:00
tools ktest.pl: Prevent recursion of default variable options 2025-08-28 16:21:26 +02:00
usr kbuild: hdrcheck: fix cross build with clang 2025-07-17 18:24:51 +02:00
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS platform: Add Surface platform directory 2025-06-27 11:02:56 +01:00
Makefile kbuild: add $(CLANG_FLAGS) to KBUILD_CPPFLAGS 2025-08-28 16:21:33 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.