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Filename Latest commit message Latest commit date
Daniel Axtens 1c44e6e09d kernel/relay.c: handle alloc_percpu returning NULL in relay_open
commit 54e200ab40fc14c863bcc80a51e20b7906608fce upstream.

alloc_percpu() may return NULL, which means chan->buf may be set to NULL.
In that case, when we do *per_cpu_ptr(chan->buf, ...), we dereference an
invalid pointer:

  BUG: Unable to handle kernel data access at 0x7dae0000
  Faulting instruction address: 0xc0000000003f3fec
  ...
  NIP relay_open+0x29c/0x600
  LR relay_open+0x270/0x600
  Call Trace:
     relay_open+0x264/0x600 (unreliable)
     __blk_trace_setup+0x254/0x600
     blk_trace_setup+0x68/0xa0
     sg_ioctl+0x7bc/0x2e80
     do_vfs_ioctl+0x13c/0x1300
     ksys_ioctl+0x94/0x130
     sys_ioctl+0x48/0xb0
     system_call+0x5c/0x68

Check if alloc_percpu returns NULL.

This was found by syzkaller both on x86 and powerpc, and the reproducer
it found on powerpc is capable of hitting the issue as an unprivileged
user.

Fixes: 017c59c042 ("relay: Use per CPU constructs for the relay channel buffer pointers")
Reported-by: syzbot+1e925b4b836afe85a1c6@syzkaller-ppc64.appspotmail.com
Reported-by: syzbot+587b2421926808309d21@syzkaller-ppc64.appspotmail.com
Reported-by: syzbot+58320b7171734bf79d26@syzkaller.appspotmail.com
Reported-by: syzbot+d6074fb08bdb2e010520@syzkaller.appspotmail.com
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Akash Goel <akash.goel@intel.com>
Cc: Andrew Donnellan <ajd@linux.ibm.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Salvatore Bonaccorso <carnil@debian.org>
Cc: <stable@vger.kernel.org>	[4.10+]
Link: http://lkml.kernel.org/r/20191219121256.26480-1-dja@axtens.net
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-07 13:18:47 +02:00
arch mm: Fix mremap not considering huge pmd devmap 2020-06-07 13:18:46 +02:00
block Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT" 2020-06-03 08:21:27 +02:00
certs
crypto gcc-10: avoid shadowing standard library 'free()' in crypto 2020-05-20 08:20:29 +02:00
Documentation USB: hub: Revert commit bd0e6c9614 ("usb: hub: try old enumeration scheme first for high speed devices") 2020-04-29 16:33:14 +02:00
drivers mt76: mt76x02u: Add support for newer versions of the XBox One wifi adapter 2020-06-07 13:18:47 +02:00
fs fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info() 2020-06-03 08:21:27 +02:00
include netfilter: nf_conntrack_pptp: fix compilation warning with W=1 build 2020-06-03 08:21:39 +02:00
init x86: Fix early boot crash on gcc-10, third try 2020-05-20 08:20:34 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel kernel/relay.c: handle alloc_percpu returning NULL in relay_open 2020-06-07 13:18:47 +02:00
lib vsprintf: don't obfuscate NULL and error pointers 2020-05-27 17:46:43 +02:00
LICENSES
mm mm: Fix mremap not considering huge pmd devmap 2020-06-07 13:18:46 +02:00
net netfilter: nf_conntrack_pptp: fix compilation warning with W=1 build 2020-06-03 08:21:39 +02:00
samples samples: bpf: Fix build error 2020-06-03 08:21:15 +02:00
scripts kbuild: Remove debug info from kallsyms linking 2020-05-27 17:46:44 +02:00
security exec: Always set cap_ambient in cap_bprm_set_creds 2020-06-03 08:21:23 +02:00
sound ALSA: hda/realtek - Add new codec supported for ALC287 2020-06-03 08:21:24 +02:00
tools perf: Make perf able to build with latest libbfd 2020-06-03 08:21:39 +02:00
usr
virt KVM: arm: vgic: Synchronize the whole guest on GIC{D,R}_I{S,C}ACTIVER read 2020-05-20 08:20:04 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 5.4.44 2020-06-03 08:21:39 +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.