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

Status: upstream: reported C repro on 2025/01/04 22:41
Bug presence: origin:lts
[Documentation on labels]
Reported-by: syzbot+04a3bfe287000b1a5529@syzkaller.appspotmail.com
First crash: 640d, last: 18h05m
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/01/06 lts (merge base) a08241812f21 C [report] KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/01/06 upstream (ToT) 9d89551994a4 C Didn't crash
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 KASAN: slab-out-of-bounds Read in tc_setup_flow_action 17 syz, C 2883 6h22m 640d 0/2 upstream: reported C repro on 2025/01/04 22:42

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/0x3200 net/sched/cls_api.c:3633
Read of size 8 at addr ffff88810ad2fec0 by task syz-executor417/303

CPU: 0 PID: 303 Comm: syz-executor417 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
 is_tcf_tunnel_set include/net/tc_act/tc_tunnel_key.h:33 [inline]
 tc_setup_flow_action+0x88e/0x3200 net/sched/cls_api.c:3633
 mall_replace_hw_filter+0x2db/0x8d0 net/sched/cls_matchall.c:100
 mall_change+0x544/0x760 net/sched/cls_matchall.c:235
 tc_new_tfilter+0x13df/0x1990 net/sched/cls_api.c:2138
 rtnetlink_rcv_msg+0x83c/0xcb0 net/core/rtnetlink.c:5653
 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2520
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5680
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x86c/0xa30 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x879/0xb80 net/netlink/af_netlink.c:1923
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5be/0x8f0 net/socket.c:2436
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg net/socket.c:2526 [inline]
 __x64_sys_sendmsg+0x201/0x2d0 net/socket.c:2526
 x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47
 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: 0033:0x7fc228716079
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:00007ffc276ae888 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffc276ae9b8 RCX: 00007fc228716079
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 0000000000000004
RBP: 0000000000000001 R08: 0000000000000003 R09: 00007ffc276ae9b8
R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffc276ae9a8
R13: 0000000000000002 R14: 00007fc2287a6ca0 R15: 0000000000000002
 </TASK>

Allocated by task 303:
 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_kmalloc mm/kasan/common.c:512 [inline]
 __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:521
 kasan_kmalloc include/linux/kasan.h:227 [inline]
 __kmalloc+0x13d/0x2c0 mm/slub.c:4436
 kmalloc include/linux/slab.h:624 [inline]
 kzalloc include/linux/slab.h:750 [inline]
 tcf_idr_create+0x5f/0x790 net/sched/act_api.c:478
 tcf_idr_create_from_flags+0x61/0x70 net/sched/act_api.c:536
 tcf_gact_init+0x342/0x570 net/sched/act_gact.c:107
 tcf_action_init_1+0x3fd/0x6b0 net/sched/act_api.c:1071
 tcf_action_init+0x233/0x7a0 net/sched/act_api.c:1130
 tcf_exts_validate+0x24a/0x580 net/sched/cls_api.c:3081
 mall_set_parms+0x48/0x520 net/sched/cls_matchall.c:171
 mall_change+0x478/0x760 net/sched/cls_matchall.c:229
 tc_new_tfilter+0x13df/0x1990 net/sched/cls_api.c:2138
 rtnetlink_rcv_msg+0x83c/0xcb0 net/core/rtnetlink.c:5653
 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2520
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5680
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x86c/0xa30 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x879/0xb80 net/netlink/af_netlink.c:1923
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5be/0x8f0 net/socket.c:2436
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg net/socket.c:2526 [inline]
 __x64_sys_sendmsg+0x201/0x2d0 net/socket.c:2526
 x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47
 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 ffff88810ad2fe00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 0 bytes to the right of
 192-byte region [ffff88810ad2fe00, ffff88810ad2fec0)
The buggy address belongs to the page:
page:ffffea00042b4bc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10ad2f
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea00042b4ac0 0000000300000003 ffff888100042c00
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12c00(GFP_NOIO|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 1956450146, free_ts 0
 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]
 __kmalloc+0x16a/0x2c0 mm/slub.c:4432
 __kmalloc_node include/linux/slab.h:487 [inline]
 kmalloc_array_node include/linux/slab.h:712 [inline]
 kcalloc_node include/linux/slab.h:717 [inline]
 sbitmap_init_node+0x2b7/0x720 lib/sbitmap.c:114
 blk_mq_alloc_hctx block/blk-mq.c:2870 [inline]
 blk_mq_alloc_and_init_hctx block/blk-mq.c:3255 [inline]
 blk_mq_realloc_hw_ctxs+0x717/0x1660 block/blk-mq.c:3307
 blk_mq_init_allocated_queue+0x3ea/0x1770 block/blk-mq.c:3368
 blk_mq_init_queue_data block/blk-mq.c:3203 [inline]
 blk_mq_init_queue+0x6c/0xd0 block/blk-mq.c:3213
 scsi_alloc_sdev+0x66c/0x9c0 drivers/scsi/scsi_scan.c:319
 scsi_probe_and_add_lun+0x180/0x35d0 drivers/scsi/scsi_scan.c:1156
 __scsi_scan_target+0x1d2/0xb70 drivers/scsi/scsi_scan.c:1637
 scsi_scan_channel drivers/scsi/scsi_scan.c:1725 [inline]
 scsi_scan_host_selected+0x34e/0x600 drivers/scsi/scsi_scan.c:1754
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88810ad2fd80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88810ad2fe00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88810ad2fe80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                           ^
 ffff88810ad2ff00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810ad2ff80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (2693):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/06 05:00 android13-5.15-lts f5eaed2bbe33 f7710056 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/06/28 02:40 android13-5.15-lts c85054db4618 fb92f11c .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/06/15 19:11 android13-5.15-lts b4be5dda13e9 50bb0618 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/03/07 07:23 android13-5.15-lts f55534477be4 5cb44a80 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/02/03 03:12 android13-5.15-lts 7e1070528954 d78927dd .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/10/26 01:07 android13-5.15-lts 1edb21e89ce4 c0460fcd .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/07/22 13:42 android13-5.15-lts a71626bd56a5 1555463b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/04/15 13:25 android13-5.15-lts 610bd6013c81 23b969b7 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/01/05 06:43 android13-5.15-lts af461d0249a8 f3558dbf .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/01/04 22:36 android13-5.15-lts af461d0249a8 f3558dbf .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/06 04:44 android13-5.15-lts f5eaed2bbe33 f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/05 16:09 android13-5.15-lts f5eaed2bbe33 af63e995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/05 13:36 android13-5.15-lts f5eaed2bbe33 af63e995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/05 02:31 android13-5.15-lts f5eaed2bbe33 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/02 21:00 android13-5.15-lts f5eaed2bbe33 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/02 16:35 android13-5.15-lts 9992bf4e1739 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/02 05:07 android13-5.15-lts 56b6e17ad4b1 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/01 16:09 android13-5.15-lts 56b6e17ad4b1 f5cdae2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/01 16:09 android13-5.15-lts 56b6e17ad4b1 f5cdae2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/10/01 05:25 android13-5.15-lts 17730f38b70b 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/28 08:18 android13-5.15-lts 776976664f31 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/28 03:48 android13-5.15-lts 776976664f31 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/26 17:27 android13-5.15-lts 776976664f31 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/26 04:38 android13-5.15-lts 776976664f31 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/26 01:08 android13-5.15-lts 81cf8006a12f f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/22 14:44 android13-5.15-lts 5bfe2b8c1439 e12281bd .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/17 07:00 android13-5.15-lts 5bfe2b8c1439 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/15 11:51 android13-5.15-lts 5bfe2b8c1439 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/13 19:43 android13-5.15-lts 5bfe2b8c1439 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/13 18:00 android13-5.15-lts 5bfe2b8c1439 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/13 13:29 android13-5.15-lts 5bfe2b8c1439 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/13 00:51 android13-5.15-lts 5bfe2b8c1439 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/12 13:09 android13-5.15-lts 5bfe2b8c1439 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/12 00:04 android13-5.15-lts 45bb2952b61c b6a5eeb7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/11 00:50 android13-5.15-lts 6b20b42b6635 1fe56c0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/08 12:32 android13-5.15-lts e9b8a6529ffa 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/07 04:18 android13-5.15-lts e9b8a6529ffa 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/05 22:34 android13-5.15-lts e9b8a6529ffa 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/05 04:51 android13-5.15-lts e9b8a6529ffa 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/04 18:47 android13-5.15-lts e9b8a6529ffa f65209a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/04 05:31 android13-5.15-lts e9b8a6529ffa 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/04 01:56 android13-5.15-lts e9b8a6529ffa 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/03 10:05 android13-5.15-lts e9b8a6529ffa 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/02 22:11 android13-5.15-lts 3af1e5c20882 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/02 03:47 android13-5.15-lts 7f9a109e0767 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/09/01 17:19 android13-5.15-lts 656ab6019045 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/08/31 13:28 android13-5.15-lts 54850912d011 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/08/31 03:51 android13-5.15-lts 54850912d011 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/08/30 23:23 android13-5.15-lts 54850912d011 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/08/30 20:03 android13-5.15-lts 54850912d011 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/08/30 18:31 android13-5.15-lts 54850912d011 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2026/08/30 14:45 android13-5.15-lts 54850912d011 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
2025/01/04 22:20 android13-5.15-lts af461d0249a8 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in tc_setup_flow_action
* Struck through repros no longer work on HEAD.