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Ignat Korchagin 6cd4a78d96 net: do not leave a dangling sk pointer, when socket creation fails
It is possible to trigger a use-after-free by:
  * attaching an fentry probe to __sock_release() and the probe calling the
    bpf_get_socket_cookie() helper
  * running traceroute -I 1.1.1.1 on a freshly booted VM

A KASAN enabled kernel will log something like below (decoded and stripped):
==================================================================
BUG: KASAN: slab-use-after-free in __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
Read of size 8 at addr ffff888007110dd8 by task traceroute/299

CPU: 2 PID: 299 Comm: traceroute Tainted: G            E      6.10.0-rc2+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
dump_stack_lvl (lib/dump_stack.c:117 (discriminator 1))
print_report (mm/kasan/report.c:378 mm/kasan/report.c:488)
? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
kasan_report (mm/kasan/report.c:603)
? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189)
__sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
bpf_get_socket_ptr_cookie (./arch/x86/include/asm/preempt.h:94 ./include/linux/sock_diag.h:42 net/core/filter.c:5094 net/core/filter.c:5092)
bpf_prog_875642cf11f1d139___sock_release+0x6e/0x8e
bpf_trampoline_6442506592+0x47/0xaf
__sock_release (net/socket.c:652)
__sock_create (net/socket.c:1601)
...
Allocated by task 299 on cpu 2 at 78.328492s:
kasan_save_stack (mm/kasan/common.c:48)
kasan_save_track (mm/kasan/common.c:68)
__kasan_slab_alloc (mm/kasan/common.c:312 mm/kasan/common.c:338)
kmem_cache_alloc_noprof (mm/slub.c:3941 mm/slub.c:4000 mm/slub.c:4007)
sk_prot_alloc (net/core/sock.c:2075)
sk_alloc (net/core/sock.c:2134)
inet_create (net/ipv4/af_inet.c:327 net/ipv4/af_inet.c:252)
__sock_create (net/socket.c:1572)
__sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706)
__x64_sys_socket (net/socket.c:1718)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Freed by task 299 on cpu 2 at 78.328502s:
kasan_save_stack (mm/kasan/common.c:48)
kasan_save_track (mm/kasan/common.c:68)
kasan_save_free_info (mm/kasan/generic.c:582)
poison_slab_object (mm/kasan/common.c:242)
__kasan_slab_free (mm/kasan/common.c:256)
kmem_cache_free (mm/slub.c:4437 mm/slub.c:4511)
__sk_destruct (net/core/sock.c:2117 net/core/sock.c:2208)
inet_create (net/ipv4/af_inet.c:397 net/ipv4/af_inet.c:252)
__sock_create (net/socket.c:1572)
__sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706)
__x64_sys_socket (net/socket.c:1718)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Fix this by clearing the struct socket reference in sk_common_release() to cover
all protocol families create functions, which may already attached the
reference to the sk object with sock_init_data().

Fixes: c5dbb89fc2 ("bpf: Expose bpf_get_socket_cookie to tracing programs")
Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/netdev/20240613194047.36478-1-kuniyu@amazon.com/T/
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240617210205.67311-1-ignat@cloudflare.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-20 10:43:14 +02:00
arch memblock: fix validation of NUMA coverage 2024-06-13 10:09:29 -07:00
block blk-throttle: Fix incorrect display of io.max 2024-05-30 19:44:29 -06:00
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 for-linus-2024060801 2024-06-08 10:48:11 -07:00
drivers ice: Fix VSI list rule with ICE_SW_LKUP_LAST type 2024-06-19 17:20:06 -07:00
fs NFS client bugfixes for Linux 6.10 2024-06-13 11:07:32 -07:00
include bpf-for-netdev 2024-06-14 17:57:10 -07:00
init Driver core changes for 6.10-rc1 2024-05-22 12:13:40 -07:00
io_uring io_uring: fix possible deadlock in io_register_iowq_max_workers() 2024-06-04 07:39:17 -06:00
ipc Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
kernel bpf-for-netdev 2024-06-14 17:57:10 -07:00
lib Including fixes from BPF and big collection of fixes for WiFi core 2024-06-06 09:55:27 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm memblock: fix validation of NUMA coverage 2024-06-13 10:09:29 -07:00
net net: do not leave a dangling sk pointer, when socket creation fails 2024-06-20 10:43:14 +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 Kbuild fixes for v6.10 (second) 2024-06-08 10:12:33 -07:00
security tomoyo: update project links 2024-06-03 22:43:11 +09:00
sound ALSA: seq: ump: Fix swapped song position pointer data 2024-05-31 09:51:44 +02:00
tools selftests: openvswitch: Set value to nla flags. 2024-06-19 13:10:53 +01:00
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 clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap bpf-for-netdev 2024-06-14 17:57:10 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS bpf-for-netdev 2024-06-14 17:57:10 -07:00
Makefile Linux 6.10-rc3 2024-06-09 14:19:43 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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.