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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: 295d, last: 20h40m
▶ ▼ 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 C 1588 12h40m 295d 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+0x842/0x3280 net/sched/cls_api.c:3639
Read of size 8 at addr ffff88810f67c3c0 by task syz.2.17/369

CPU: 0 PID: 369 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x169/0x1d8 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+0xe2/0x130 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+0x842/0x3280 net/sched/cls_api.c:3639
 mall_replace_hw_filter+0x293/0x810 net/sched/cls_matchall.c:100
 mall_change+0x528/0x750 net/sched/cls_matchall.c:236
 tc_new_tfilter+0x13f6/0x1a10 net/sched/cls_api.c:2134
 rtnetlink_rcv_msg+0x800/0xb90 net/core/rtnetlink.c:5601
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2503
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f56f9d3ec29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdc73dc318 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f56f9f85fa0 RCX: 00007f56f9d3ec29
RDX: 0000000000000000 RSI: 0000200000000580 RDI: 0000000000000004
RBP: 00007f56f9dc1e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f56f9f85fa0 R14: 00007f56f9f85fa0 R15: 0000000000000003

Allocated by task 369:
 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+0xda/0x110 mm/kasan/common.c:518
 kasan_kmalloc include/linux/kasan.h:254 [inline]
 __kmalloc+0x1a7/0x330 mm/slub.c:4038
 kmalloc include/linux/slab.h:557 [inline]
 kzalloc include/linux/slab.h:664 [inline]
 tcf_idr_create+0x5f/0x790 net/sched/act_api.c:430
 tcf_idr_create_from_flags+0x61/0x70 net/sched/act_api.c:488
 tcf_gact_init+0x2b4/0x520 net/sched/act_gact.c:102
 tcf_action_init_1+0x3e1/0x670 net/sched/act_api.c:1052
 tcf_action_init+0x1e6/0x700 net/sched/act_api.c:1109
 tcf_exts_validate+0x215/0x510 net/sched/cls_api.c:3086
 mall_set_parms+0x4b/0x410 net/sched/cls_matchall.c:171
 mall_change+0x45c/0x750 net/sched/cls_matchall.c:230
 tc_new_tfilter+0x13f6/0x1a10 net/sched/cls_api.c:2134
 rtnetlink_rcv_msg+0x800/0xb90 net/core/rtnetlink.c:5601
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2503
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466
 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 ffff88810f67c300
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 0 bytes to the right of
 192-byte region [ffff88810f67c300, ffff88810f67c3c0)
The buggy address belongs to the page:
page:ffffea00043d9f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10f67c
flags: 0x4000000000000200(slab)
raw: 4000000000000200 ffffea00043d9d80 0000000600000006 ffff888100043380
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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 96, ts 5863729433, free_ts 5863707497
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370
 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+0x2a6/0x450 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+0x1b3/0x2e0 mm/slub.c:2977
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:664 [inline]
 kernfs_fop_open+0x343/0xb30 fs/kernfs/file.c:628
 do_dentry_open+0x793/0x1090 fs/open.c:819
 vfs_open+0x73/0x80 fs/open.c:942
 do_open fs/namei.c:3391 [inline]
 path_openat+0x27ad/0x3160 fs/namei.c:3509
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3536
 do_sys_openat2+0x14c/0x6d0 fs/open.c:1217
 do_sys_open fs/open.c:1233 [inline]
 __do_sys_openat fs/open.c:1249 [inline]
 __se_sys_openat fs/open.c:1244 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1244
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336
 free_unref_page mm/page_alloc.c:3391 [inline]
 free_the_page mm/page_alloc.c:5429 [inline]
 __free_pages+0x14b/0x380 mm/page_alloc.c:5440
 free_pages+0x82/0x90 mm/page_alloc.c:5451
 selinux_genfs_get_sid+0x20b/0x250 security/selinux/hooks.c:1326
 inode_doinit_with_dentry+0x86d/0xd70 security/selinux/hooks.c:1523
 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6389
 security_d_instantiate+0x9e/0xf0 security/security.c:1980
 d_splice_alias+0x6d/0x390 fs/dcache.c:3036
 kernfs_iop_lookup+0x2c5/0x310 fs/kernfs/dir.c:1178
 lookup_open fs/namei.c:3226 [inline]
 open_last_lookups fs/namei.c:3317 [inline]
 path_openat+0x1127/0x3160 fs/namei.c:3506
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3536
 do_sys_openat2+0x14c/0x6d0 fs/open.c:1217
 do_sys_open fs/open.c:1233 [inline]
 __do_sys_openat fs/open.c:1249 [inline]
 __se_sys_openat fs/open.c:1244 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1244
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff88810f67c280: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88810f67c300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88810f67c380: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                           ^
 ffff88810f67c400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88810f67c480: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (1609):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2025/10/26 08:07 android13-5.10-lts 2ece552169c2 c0460fcd .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
2025/10/25 01:47 android13-5.10-lts 2ece552169c2 c0460fcd .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
2025/10/24 20:36 android13-5.10-lts 2ece552169c2 c0460fcd .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
2025/10/23 22:30 android13-5.10-lts 2ece552169c2 c0460fcd .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
2025/10/23 16:29 android13-5.10-lts 2ece552169c2 c0460fcd .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
2025/10/22 22:04 android13-5.10-lts 2ece552169c2 c0460fcd .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
2025/10/22 19:46 android13-5.10-lts 2ece552169c2 c0460fcd .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
2025/10/22 05:20 android13-5.10-lts 2ece552169c2 252fbbad .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
2025/10/21 23:16 android13-5.10-lts 2ece552169c2 9832ed61 .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
2025/10/21 17:21 android13-5.10-lts 2ece552169c2 9832ed61 .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
2025/10/20 08:39 android13-5.10-lts 2ece552169c2 1c8c8cd8 .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
2025/10/20 05:46 android13-5.10-lts 2ece552169c2 1c8c8cd8 .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
2025/10/19 18:54 android13-5.10-lts 2ece552169c2 1c8c8cd8 .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
2025/10/19 18:52 android13-5.10-lts 2ece552169c2 1c8c8cd8 .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
2025/10/19 11:26 android13-5.10-lts 2ece552169c2 1c8c8cd8 .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
2025/10/18 02:18 android13-5.10-lts 2ece552169c2 1c8c8cd8 .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
2025/10/16 04:43 android13-5.10-lts 2ece552169c2 19568248 .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
2025/10/15 18:00 android13-5.10-lts 2ece552169c2 19568248 .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
2025/10/14 18:41 android13-5.10-lts 2ece552169c2 b6605ba8 .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
2025/10/14 17:30 android13-5.10-lts 2ece552169c2 b6605ba8 .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
2025/10/13 10:39 android13-5.10-lts 2ece552169c2 ff1712fe .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
2025/10/13 07:29 android13-5.10-lts 2ece552169c2 ff1712fe .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
2025/10/13 04:38 android13-5.10-lts 2ece552169c2 ff1712fe .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
2025/10/13 03:09 android13-5.10-lts 2ece552169c2 ff1712fe .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
2025/10/12 18:08 android13-5.10-lts 2ece552169c2 ff1712fe .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
2025/10/12 18:08 android13-5.10-lts 2ece552169c2 ff1712fe .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
2025/10/11 08:48 android13-5.10-lts 2ece552169c2 ff1712fe .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
2025/10/10 21:16 android13-5.10-lts 2ece552169c2 ff1712fe .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
2025/10/09 16:35 android13-5.10-lts 2ece552169c2 7e2882b3 .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
2025/10/08 19:08 android13-5.10-lts 2ece552169c2 7e2882b3 .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
2025/10/08 17:47 android13-5.10-lts 2ece552169c2 7e2882b3 .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
2025/10/08 06:57 android13-5.10-lts 2ece552169c2 7e2882b3 .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
2025/10/07 19:58 android13-5.10-lts 2ece552169c2 8ef35d49 .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
2025/10/07 07:48 android13-5.10-lts 0a91f603159e 8ef35d49 .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
2025/10/07 02:00 android13-5.10-lts 0a91f603159e 8ef35d49 .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
2025/10/06 21:57 android13-5.10-lts 0a91f603159e 91305dbe .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
2025/10/05 02:04 android13-5.10-lts 0a91f603159e 49379ee0 .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
2025/10/03 22:51 android13-5.10-lts 0a91f603159e 49379ee0 .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
2025/10/03 16:50 android13-5.10-lts 0a91f603159e 49379ee0 .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
2025/10/03 07:29 android13-5.10-lts 0a91f603159e 49379ee0 .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
2025/10/02 17:47 android13-5.10-lts 0a91f603159e 49379ee0 .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
2025/10/01 00:12 android13-5.10-lts 0a91f603159e 65a0eece .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
2025/09/30 17:25 android13-5.10-lts 0a91f603159e 65a0eece .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
2025/09/30 12:31 android13-5.10-lts 0a91f603159e 86341da6 .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
2025/09/29 12:53 android13-5.10-lts 911f602c2237 86341da6 .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.