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Kuniyuki Iwashima 66b60b0c8c dccp/tcp: Unhash sk from ehash for tb2 alloc failure after check_estalblished().
syzkaller reported a warning [0] in inet_csk_destroy_sock() with no
repro.

  WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);

However, the syzkaller's log hinted that connect() failed just before
the warning due to FAULT_INJECTION.  [1]

When connect() is called for an unbound socket, we search for an
available ephemeral port.  If a bhash bucket exists for the port, we
call __inet_check_established() or __inet6_check_established() to check
if the bucket is reusable.

If reusable, we add the socket into ehash and set inet_sk(sk)->inet_num.

Later, we look up the corresponding bhash2 bucket and try to allocate
it if it does not exist.

Although it rarely occurs in real use, if the allocation fails, we must
revert the changes by check_established().  Otherwise, an unconnected
socket could illegally occupy an ehash entry.

Note that we do not put tw back into ehash because sk might have
already responded to a packet for tw and it would be better to free
tw earlier under such memory presure.

[0]:
WARNING: CPU: 0 PID: 350830 at net/ipv4/inet_connection_sock.c:1193 inet_csk_destroy_sock (net/ipv4/inet_connection_sock.c:1193)
Modules linked in:
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:inet_csk_destroy_sock (net/ipv4/inet_connection_sock.c:1193)
Code: 41 5c 41 5d 41 5e e9 2d 4a 3d fd e8 28 4a 3d fd 48 89 ef e8 f0 cd 7d ff 5b 5d 41 5c 41 5d 41 5e e9 13 4a 3d fd e8 0e 4a 3d fd <0f> 0b e9 61 fe ff ff e8 02 4a 3d fd 4c 89 e7 be 03 00 00 00 e8 05
RSP: 0018:ffffc9000b21fd38 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000009e78 RCX: ffffffff840bae40
RDX: ffff88806e46c600 RSI: ffffffff840bb012 RDI: ffff88811755cca8
RBP: ffff88811755c880 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000009e78 R11: 0000000000000000 R12: ffff88811755c8e0
R13: ffff88811755c892 R14: ffff88811755c918 R15: 0000000000000000
FS:  00007f03e5243800(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32f21000 CR3: 0000000112ffe001 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
 <TASK>
 ? inet_csk_destroy_sock (net/ipv4/inet_connection_sock.c:1193)
 dccp_close (net/dccp/proto.c:1078)
 inet_release (net/ipv4/af_inet.c:434)
 __sock_release (net/socket.c:660)
 sock_close (net/socket.c:1423)
 __fput (fs/file_table.c:377)
 __fput_sync (fs/file_table.c:462)
 __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
 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:129)
RIP: 0033:0x7f03e53852bb
Code: 03 00 00 00 0f 05 48 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 43 c9 f5 ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 c9 f5 ff 8b 44
RSP: 002b:00000000005dfba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f03e53852bb
RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000167c
R10: 0000000008a79680 R11: 0000000000000293 R12: 00007f03e4e43000
R13: 00007f03e4e43170 R14: 00007f03e4e43178 R15: 00007f03e4e43170
 </TASK>

[1]:
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 350833 Comm: syz-executor.1 Not tainted 6.7.0-12272-g2121c43f88f5 #9
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1))
 should_fail_ex (lib/fault-inject.c:52 lib/fault-inject.c:153)
 should_failslab (mm/slub.c:3748)
 kmem_cache_alloc (mm/slub.c:3763 mm/slub.c:3842 mm/slub.c:3867)
 inet_bind2_bucket_create (net/ipv4/inet_hashtables.c:135)
 __inet_hash_connect (net/ipv4/inet_hashtables.c:1100)
 dccp_v4_connect (net/dccp/ipv4.c:116)
 __inet_stream_connect (net/ipv4/af_inet.c:676)
 inet_stream_connect (net/ipv4/af_inet.c:747)
 __sys_connect_file (net/socket.c:2048 (discriminator 2))
 __sys_connect (net/socket.c:2065)
 __x64_sys_connect (net/socket.c:2072)
 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:129)
RIP: 0033:0x7f03e5284e5d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48
RSP: 002b:00007f03e4641cc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00000000004bbf80 RCX: 00007f03e5284e5d
RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000004bbf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 000000000000000b R14: 00007f03e52e5530 R15: 0000000000000000
 </TASK>

Reported-by: syzkaller <syzkaller@googlegroups.com>
Fixes: 28044fc1d4 ("net: Add a bhash2 table hashed by port and address")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-16 09:41:54 +00:00
arch xen: branch for v6.8-rc5 2024-02-15 11:33:35 -08:00
block blk-iocost: Fix an UBSAN shift-out-of-bounds warning 2024-02-08 10:11:39 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto crypto: algif_hash - Remove bogus SGL free on zero-length error path 2024-02-02 18:08:12 +08:00
Documentation Including fixes from can, wireless and netfilter. 2024-02-15 11:39:27 -08:00
drivers Including fixes from can, wireless and netfilter. 2024-02-15 11:39:27 -08:00
fs for-6.8-rc4-tag 2024-02-14 15:47:02 -08:00
include net: bridge: switchdev: Skip MDB replays of deferred events on offload 2024-02-16 09:36:37 +00:00
init update workarounds for gcc "asm goto" issue 2024-02-15 11:14:33 -08:00
io_uring io_uring/net: fix sr->len for IORING_OP_RECV with MSG_WAITALL and buffers 2024-02-01 06:42:36 -07:00
ipc shm: Slim down dependencies 2023-12-20 19:26:31 -05:00
kernel - Make sure a warning is issued when a hrtimer gets queued after the 2024-02-11 11:44:14 -08:00
lib linux_kselftest-kunit-fixes-6.8-rc5 2024-02-14 15:34:03 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm/memory: Use exception ip to search exception tables 2024-02-12 23:04:42 +01:00
net dccp/tcp: Unhash sk from ehash for tb2 alloc failure after check_estalblished(). 2024-02-16 09:41:54 +00:00
rust Rust changes for v6.8 2024-01-11 13:05:41 -08:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-09 15:57:48 -08:00
scripts Kbuild fixes for v6.8 2024-02-01 11:57:42 -08:00
security lsm/stable-6.8 PR 20240131 2024-02-01 10:00:28 -08:00
sound ASoC: Fixes for v6.8 2024-02-01 19:40:42 +01:00
tools Including fixes from can, wireless and netfilter. 2024-02-15 11:39:27 -08:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt Generic: 2024-01-17 13:03:37 -08:00
.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 get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.mailmap Including fixes from can, wireless and netfilter. 2024-02-15 11:39:27 -08:00
.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: supplement of zswap maintainers update 2024-01-25 23:52:21 -08:00
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 Including fixes from can, wireless and netfilter. 2024-02-15 11:39:27 -08:00
Makefile Linux 6.8-rc4 2024-02-11 12:18:13 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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 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.