system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-07-08 20:29:39 +00:00
Code Issues Packages Projects Releases Wiki Activity
1,279,051 Commits 6 Branches 844 Tags 5.7 GiB
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%
97e1db06c7
Go to file
Kuniyuki Iwashima 97e1db06c7 af_unix: Annotate data-race around unix_sk(sk)->addr. 
Once unix_sk(sk)->addr is assigned under net->unx.table.locks and
unix_sk(sk)->bindlock, *(unix_sk(sk)->addr) and unix_sk(sk)->path are
fully set up, and unix_sk(sk)->addr is never changed.

unix_getname() and unix_copy_addr() access the two fields locklessly,
and commit ae3b564179 ("missing barriers in some of unix_sock ->addr
and ->path accesses") added smp_store_release() and smp_load_acquire()
pairs.

In other functions, we still read unix_sk(sk)->addr locklessly to check
if the socket is bound, and KCSAN complains about it.  [0]

Given these functions have no dependency for *(unix_sk(sk)->addr) and
unix_sk(sk)->path, READ_ONCE() is enough to annotate the data-race.

Note that it is safe to access unix_sk(sk)->addr locklessly if the socket
is found in the hash table.  For example, the lockless read of otheru->addr
in unix_stream_connect() is safe.

Note also that newu->addr there is of the child socket that is still not
accessible from userspace, and smp_store_release() publishes the address
in case the socket is accept()ed and unix_getname() / unix_copy_addr()
is called.

[0]:
BUG: KCSAN: data-race in unix_bind / unix_listen

write (marked) to 0xffff88805f8d1840 of 8 bytes by task 13723 on cpu 0:
 __unix_set_addr_hash net/unix/af_unix.c:329 [inline]
 unix_bind_bsd net/unix/af_unix.c:1241 [inline]
 unix_bind+0x881/0x1000 net/unix/af_unix.c:1319
 __sys_bind+0x194/0x1e0 net/socket.c:1847
 __do_sys_bind net/socket.c:1858 [inline]
 __se_sys_bind net/socket.c:1856 [inline]
 __x64_sys_bind+0x40/0x50 net/socket.c:1856
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x46/0x4e

read to 0xffff88805f8d1840 of 8 bytes by task 13724 on cpu 1:
 unix_listen+0x72/0x180 net/unix/af_unix.c:734
 __sys_listen+0xdc/0x160 net/socket.c:1881
 __do_sys_listen net/socket.c:1890 [inline]
 __se_sys_listen net/socket.c:1888 [inline]
 __x64_sys_listen+0x2e/0x40 net/socket.c:1888
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x46/0x4e

value changed: 0x0000000000000000 -> 0xffff88807b5b1b40

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13724 Comm: syz-executor.4 Not tainted 6.8.0-12822-gcd51db110a7e #12
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240522154002.77857-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-27 11:46:31 +02:00
arch tracing: Remove second argument of __assign_str() 2024-05-23 12:28:01 -07:00
block Compactifying bdev flags 2024-05-21 13:02:56 -07:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto This push fixes a bug in the new ecc P521 code as well as a buggy 2024-05-20 08:47:54 -07:00
Documentation arm64 fixes for -rc1 2024-05-23 12:09:22 -07:00
drivers enic: Validate length of nl attributes in enic_set_vf_port 2024-05-27 11:18:01 +02:00
fs tracing: Remove second argument of __assign_str() 2024-05-23 12:28:01 -07:00
include net/mlx5: Fix MTMP register capability offset in MCAM register 2024-05-24 13:27:07 +01:00
init Driver core changes for 6.10-rc1 2024-05-22 12:13:40 -07:00
io_uring Assorted commits that had missed the last merge window... 2024-05-21 13:11:44 -07:00
ipc Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
kernel tracing: Minor last minute fixes 2024-05-23 12:36:38 -07:00
lib - A series ("kbuild: enable more warnings by default") from Arnd 2024-05-22 18:59:29 -07:00
LICENSES
mm A series from Dave Chinner which cleans up and fixes the handling of 2024-05-22 17:32:04 -07:00
net af_unix: Annotate data-race around unix_sk(sk)->addr. 2024-05-27 11:46:31 +02:00
rust LoongArch changes for v6.10 2024-05-22 09:43:07 -07:00
samples tracing/treewide: Remove second parameter of __assign_str() 2024-05-22 20:14:47 -04:00
scripts - A series ("kbuild: enable more warnings by default") from Arnd 2024-05-22 18:59:29 -07:00
security KEYS: trusted: Do not use WARN when encode fails 2024-05-21 02:35:10 +03:00
sound tracing: Remove second argument of __assign_str() 2024-05-23 12:28:01 -07:00
tools selftests: hsr: Fix "File exists" errors for hsr_ping 2024-05-27 11:44:42 +02:00
usr kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
virt The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
.clang-format
.cocciconfig
.editorconfig
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap Another not-too-busy cycle for documentation, including: 2024-05-13 10:51:53 -07:00
.rustfmt.toml
COPYING
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild
Kconfig
MAINTAINERS virtio: features, fixes, cleanups 2024-05-23 12:04:36 -07:00
Makefile arch: add ARCH_HAS_KERNEL_FPU_SUPPORT 2024-05-19 14:36:17 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.