[Android 5.15] KASAN: slab-out-of-bounds Read in sk_skb_adjust_room

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f5eaed2bbe33 Merge 9f30ba9aa027 ("tcp: clear sock_ops cb f..
git tree: android13-5.15-lts
console+strace: https://syzkaller.appspot.com/x/log.txt?x=14a70f25580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b0ecca01ee1a007b
dashboard link: https://syzkaller.appspot.com/bug?extid=4cd99872eba48e59d844
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=172cdec9580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1641cff5580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0b69ef6197fe/disk-f5eaed2b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/254a4c27bfd7/vmlinux-f5eaed2b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f44f2cf9e40b/bzImage-f5eaed2b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4cd998...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in tls_get_ctx include/net/tls.h:507 [inline]
BUG: KASAN: slab-out-of-bounds in tls_sw_has_ctx_rx include/net/tls.h:615 [inline]
BUG: KASAN: slab-out-of-bounds in ____sk_skb_adjust_room net/core/filter.c:3646 [inline]
BUG: KASAN: slab-out-of-bounds in sk_skb_adjust_room+0x389/0x5c0 net/core/filter.c:3623
Read of size 8 at addr ffff88811f128528 by task syz-executor370/304

CPU: 1 PID: 304 Comm: syz-executor370 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
<TASK>
__dump_stack+0x21/0x30 lib/dump_stack.c:88
dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:427 [inline]
kasan_report+0x10f/0x150 mm/kasan/report.c:444
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
tls_get_ctx include/net/tls.h:507 [inline]
tls_sw_has_ctx_rx include/net/tls.h:615 [inline]
____sk_skb_adjust_room net/core/filter.c:3646 [inline]
sk_skb_adjust_room+0x389/0x5c0 net/core/filter.c:3623
bpf_prog_e15ab8bd9cea3c06+0x19/0x9cc
bpf_dispatcher_nop_func include/linux/bpf.h:786 [inline]
__bpf_prog_run include/linux/filter.h:628 [inline]
bpf_prog_run include/linux/filter.h:635 [inline]
bpf_prog_run_pin_on_cpu include/linux/filter.h:652 [inline]
sk_psock_verdict_recv+0x245/0x7f0 net/core/skmsg.c:1233
unix_read_sock+0x108/0x2d0 net/unix/af_unix.c:2439
unix_stream_read_sock+0x61/0x90 net/unix/af_unix.c:2615
sk_psock_verdict_data_ready+0x167/0x1d0 net/core/skmsg.c:1256
unix_stream_sendmsg+0x7d1/0xc90 net/unix/af_unix.c:2117
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
__sys_sendto+0x46d/0x620 net/socket.c:2063
__do_sys_sendto net/socket.c:2075 [inline]
__se_sys_sendto net/socket.c:2071 [inline]
__x64_sys_sendto+0xe5/0x100 net/socket.c:2071
x64_sys_call+0x178/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:45
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd6c5518e79
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 00 00 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 c7 c1 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff219d7898 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fff219d79d8 RCX: 00007fd6c5518e79
RDX: 0000000000000001 RSI: 0000200000000800 RDI: 0000000000000004
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff219d79c8
R13: 0000000000000002 R14: 00007fd6c55a9ca0 R15: 0000000000000002
</TASK>

Allocated by task 304:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:433 [inline]
__kasan_slab_alloc+0xb7/0xe0 mm/kasan/common.c:466
kasan_slab_alloc include/linux/kasan.h:217 [inline]
slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550
slab_alloc_node mm/slub.c:3245 [inline]
slab_alloc mm/slub.c:3255 [inline]
kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260
sk_prot_alloc+0x5f/0x320 net/core/sock.c:1861
sk_alloc+0x38/0x430 net/core/sock.c:1927
unix_create1+0xb4/0x610 net/unix/af_unix.c:-1
unix_create+0x149/0x200 net/unix/af_unix.c:933
__sock_create+0x38d/0x7a0 net/socket.c:1486
sock_create net/socket.c:1542 [inline]
__sys_socketpair+0x1a1/0x590 net/socket.c:1642
__do_sys_socketpair net/socket.c:1695 [inline]
__se_sys_socketpair net/socket.c:1692 [inline]
__x64_sys_socketpair+0x9b/0xb0 net/socket.c:1692
x64_sys_call+0x36/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:54
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88811f128000
which belongs to the cache UNIX-STREAM of size 1216
The buggy address is located 104 bytes to the right of
1216-byte region [ffff88811f128000, ffff88811f1284c0)
The buggy address belongs to the page:
page:ffffea00047c4a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11f128
head:ffffea00047c4a00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 0000000000000000 dead000000000122 ffff8881003e7500
raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 297, ts 32288072481, free_ts 29013579392
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607
prep_new_page+0x1c/0x110 mm/page_alloc.c:2613
get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487
__alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824
alloc_slab_page mm/slub.c:-1 [inline]
allocate_slab mm/slub.c:1937 [inline]
new_slab+0xa0/0x4d0 mm/slub.c:2000
___slab_alloc+0x3ac/0x840 mm/slub.c:3033
__slab_alloc+0x49/0x90 mm/slub.c:3120
slab_alloc_node mm/slub.c:3211 [inline]
slab_alloc mm/slub.c:3255 [inline]
kmem_cache_alloc+0x138/0x260 mm/slub.c:3260
sk_prot_alloc+0x5f/0x320 net/core/sock.c:1861
sk_alloc+0x38/0x430 net/core/sock.c:1927
unix_create1+0xb4/0x610 net/unix/af_unix.c:-1
unix_stream_connect+0x308/0x1020 net/unix/af_unix.c:1357
__sys_connect_file net/socket.c:1923 [inline]
__sys_connect+0x3cb/0x450 net/socket.c:1940
__do_sys_connect net/socket.c:1950 [inline]
__se_sys_connect net/socket.c:1947 [inline]
__x64_sys_connect+0x7a/0x90 net/socket.c:1947
x64_sys_call+0x7c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:43
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
page last free stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
free_pages_prepare mm/page_alloc.c:1474 [inline]
free_pcp_prepare mm/page_alloc.c:1546 [inline]
free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3536
free_unref_page+0xae/0x540 mm/page_alloc.c:3618
free_the_page mm/page_alloc.c:805 [inline]
free_compound_page+0x78/0xa0 mm/page_alloc.c:828
destroy_compound_page include/linux/mm.h:1000 [inline]
__put_compound_page+0x77/0xb0 mm/swap.c:111
__put_page+0xbc/0xe0 mm/swap.c:127
put_page include/linux/mm.h:1306 [inline]
__skb_frag_unref include/linux/skbuff.h:3275 [inline]
skb_release_data+0x37c/0xa20 net/core/skbuff.c:673
skb_release_all net/core/skbuff.c:743 [inline]
__kfree_skb+0x50/0x70 net/core/skbuff.c:757
sk_eat_skb include/net/sock.h:2800 [inline]
tcp_recvmsg_locked+0x13d1/0x24f0 net/ipv4/tcp.c:2520
tcp_recvmsg+0x233/0x770 net/ipv4/tcp.c:2566
inet_recvmsg+0x13a/0x470 net/ipv4/af_inet.c:861
sock_recvmsg_nosec net/socket.c:967 [inline]
sock_recvmsg net/socket.c:985 [inline]
sock_read_iter+0x2c2/0x380 net/socket.c:1058
call_read_iter include/linux/fs.h:2212 [inline]
new_sync_read fs/read_write.c:404 [inline]
vfs_read+0x6c0/0xc20 fs/read_write.c:485
ksys_read+0x14a/0x260 fs/read_write.c:623
__do_sys_read fs/read_write.c:633 [inline]
__se_sys_read fs/read_write.c:631 [inline]
__x64_sys_read+0x7b/0x90 fs/read_write.c:631
x64_sys_call+0x96d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:1
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80

Memory state around the buggy address:
ffff88811f128400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88811f128480: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff88811f128500: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
^
ffff88811f128580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88811f128600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
Disabling lock debugging du


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