KASAN: slab-out-of-bounds Read in tc_setup_flow_action

Status: upstream: reported C repro on 2025/01/04 22:42
Reported-by: syzbot+7a1c3b8c6950bb246cfc@syzkaller.appspotmail.com
First crash: 669d, last: 40m
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action origin:lts 17 syz, C 2753 8h45m 669d 0/2 upstream: reported C repro on 2025/01/04 22:41

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in is_tcf_tunnel_set include/net/tc_act/tc_tunnel_key.h:33 [inline]
BUG: KASAN: slab-out-of-bounds in tc_setup_flow_action+0x88e/0x3160 net/sched/cls_api.c:3640
Read of size 8 at addr ffff88811d0866d8 by task syz-executor392/297

CPU: 1 PID: 297 Comm: syz-executor392 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x100/0x140 mm/kasan/report.c:452
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
 is_tcf_tunnel_set include/net/tc_act/tc_tunnel_key.h:33 [inline]
 tc_setup_flow_action+0x88e/0x3160 net/sched/cls_api.c:3640
 mall_replace_hw_filter+0x2db/0x8c0 net/sched/cls_matchall.c:100
 mall_change+0x546/0x770 net/sched/cls_matchall.c:236
 tc_new_tfilter+0x1487/0x1ab0 net/sched/cls_api.c:2134
 rtnetlink_rcv_msg+0x811/0xca0 net/core/rtnetlink.c:5613
 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2508
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5640
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x86c/0xa30 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x949/0xb70 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5be/0x8f0 net/socket.c:2377
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2431
 __sys_sendmsg net/socket.c:2460 [inline]
 __do_sys_sendmsg net/socket.c:2469 [inline]
 __se_sys_sendmsg net/socket.c:2467 [inline]
 __x64_sys_sendmsg+0x201/0x2d0 net/socket.c:2467
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f59c2a68079
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:00007ffc23613988 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffc23613ab8 RCX: 00007f59c2a68079
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 0000000000000004
RBP: 0000000000000001 R08: 0000000000000003 R09: 00007ffc23613ab8
R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffc23613aa8
R13: 0000000000000002 R14: 00007f59c2af8ca0 R15: 0000000000000002

Allocated by task 297:
 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:430 [inline]
 ____kasan_kmalloc mm/kasan/common.c:509 [inline]
 __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518
 kasan_kmalloc include/linux/kasan.h:254 [inline]
 __kmalloc+0x19f/0x330 mm/slub.c:4038
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:667 [inline]
 tcf_idr_create+0x5f/0x790 net/sched/act_api.c:434
 tcf_idr_create_from_flags+0x61/0x70 net/sched/act_api.c:492
 tcf_gact_init+0x2e6/0x560 net/sched/act_gact.c:107
 tcf_action_init_1+0x443/0x6d0 net/sched/act_api.c:1056
 tcf_action_init+0x227/0x780 net/sched/act_api.c:1113
 tcf_exts_validate+0x23c/0x540 net/sched/cls_api.c:3087
 mall_set_parms+0x4a/0x450 net/sched/cls_matchall.c:171
 mall_change+0x47a/0x770 net/sched/cls_matchall.c:230
 tc_new_tfilter+0x1487/0x1ab0 net/sched/cls_api.c:2134
 rtnetlink_rcv_msg+0x811/0xca0 net/core/rtnetlink.c:5613
 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2508
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5640
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x86c/0xa30 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x949/0xb70 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5be/0x8f0 net/socket.c:2377
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2431
 __sys_sendmsg net/socket.c:2460 [inline]
 __do_sys_sendmsg net/socket.c:2469 [inline]
 __se_sys_sendmsg net/socket.c:2467 [inline]
 __x64_sys_sendmsg+0x201/0x2d0 net/socket.c:2467
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff88811d086600
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 216 bytes inside of
 256-byte region [ffff88811d086600, ffff88811d086700)
The buggy address belongs to the page:
page:ffffea0004742180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11d086
head:ffffea0004742180 order:1 compound_mapcount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043200
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 224, ts 16708302739, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x176/0x190 mm/page_alloc.c:2462
 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1813 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1874
 new_slab_objects mm/slub.c:2632 [inline]
 ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796
 __slab_alloc+0x63/0xa0 mm/slub.c:2836
 slab_alloc_node mm/slub.c:2918 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 kmem_cache_alloc_trace+0x1a8/0x2e0 mm/slub.c:2977
 kmalloc include/linux/slab.h:555 [inline]
 inode_doinit_use_xattr+0x5d/0x400 security/selinux/hooks.c:1346
 inode_doinit_with_dentry+0x82c/0xd70 security/selinux/hooks.c:1475
 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6396
 security_d_instantiate+0x9e/0xf0 security/security.c:1980
 d_splice_alias+0x6d/0x390 fs/dcache.c:3038
 ext4_lookup+0x4aa/0x8c0 fs/ext4/namei.c:1858
 lookup_open fs/namei.c:3276 [inline]
 open_last_lookups fs/namei.c:3367 [inline]
 path_openat+0x145d/0x3040 fs/namei.c:3556
 do_filp_open+0x1df/0x400 fs/namei.c:3586
 do_sys_openat2+0x19f/0x750 fs/open.c:1219
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88811d086580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811d086600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88811d086680: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
                                                    ^
 ffff88811d086700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811d086780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (2983):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/25 21:21 android13-5.10-lts f61a392235e0 1d9ca40b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/26 04:30 android13-5.10-lts c5d8ec7afea2 a3c7249d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/06/15 21:07 android13-5.10-lts a36936eeef1e 50bb0618 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/05/24 20:15 android13-5.10-lts f5a34916f66d c69befb3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/02/12 22:16 android13-5.10-lts e8b14e1cefe8 504cb1bf .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/12/30 04:19 android13-5.10-lts e253c52bbdfc d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/09/20 20:09 android13-5.10-lts 911f602c2237 67c37560 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/06/12 15:10 android13-5.10-lts d76d4cd0623a 98683f8f .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/04/05 17:32 android13-5.10-lts 094fc3778d6b c53ea9c9 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/01/04 22:55 android13-5.10-lts 49e8ba0a684f f3558dbf .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/01/04 22:39 android13-5.10-lts 49e8ba0a684f f3558dbf .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/11/05 00:55 android13-5.10-lts f61a392235e0 73438ed0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/11/04 17:11 android13-5.10-lts f61a392235e0 73438ed0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/11/04 03:44 android13-5.10-lts f61a392235e0 5af5b6c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/11/03 11:15 android13-5.10-lts f61a392235e0 6969b601 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/11/03 10:01 android13-5.10-lts f61a392235e0 6969b601 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/11/01 09:21 android13-5.10-lts f61a392235e0 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/11/01 00:08 android13-5.10-lts f61a392235e0 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/31 00:23 android13-5.10-lts f61a392235e0 0ec395f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/30 10:28 android13-5.10-lts f61a392235e0 b498adee .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/28 10:47 android13-5.10-lts f61a392235e0 858db2ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/28 09:15 android13-5.10-lts f61a392235e0 96923c60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/28 08:29 android13-5.10-lts f61a392235e0 96923c60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/28 06:21 android13-5.10-lts f61a392235e0 96923c60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/28 04:53 android13-5.10-lts f61a392235e0 96923c60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/28 01:48 android13-5.10-lts f61a392235e0 96923c60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/28 00:42 android13-5.10-lts f61a392235e0 96923c60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/27 23:16 android13-5.10-lts f61a392235e0 96923c60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/27 20:55 android13-5.10-lts f61a392235e0 96923c60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/27 19:48 android13-5.10-lts f61a392235e0 96923c60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/27 18:20 android13-5.10-lts f61a392235e0 96923c60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/26 23:33 android13-5.10-lts f61a392235e0 168cb7a2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/26 08:34 android13-5.10-lts f61a392235e0 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/25 17:31 android13-5.10-lts f61a392235e0 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/24 01:29 android13-5.10-lts d3231d350eb8 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/22 07:39 android13-5.10-lts 30b93835619a 4ba27f85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/22 01:00 android13-5.10-lts 30b93835619a 4ba27f85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/21 12:15 android13-5.10-lts 30b93835619a 61c200c7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/21 12:14 android13-5.10-lts 30b93835619a 61c200c7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/20 23:44 android13-5.10-lts 30b93835619a df8746fb .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/18 23:20 android13-5.10-lts 30b93835619a 432c0077 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/17 01:09 android13-5.10-lts f5932bf046b5 432c0077 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/16 13:53 android13-5.10-lts f5932bf046b5 4c840a2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/16 08:16 android13-5.10-lts f5932bf046b5 3f2522c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/15 13:55 android13-5.10-lts f5932bf046b5 8fb0ae89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/15 04:42 android13-5.10-lts 390db4f54a67 8fb0ae89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/14 23:30 android13-5.10-lts 390db4f54a67 1a71827b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/14 16:50 android13-5.10-lts 390db4f54a67 1a71827b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/12 15:24 android13-5.10-lts b677692288f7 745a967f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/12 12:21 android13-5.10-lts b677692288f7 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/12 06:01 android13-5.10-lts b677692288f7 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/11 18:20 android13-5.10-lts b677692288f7 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/11 06:08 android13-5.10-lts b677692288f7 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/01/04 22:20 android13-5.10-lts 49e8ba0a684f f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
* Struck through repros no longer work on HEAD.