bisecting fixing commit since f9be84db09d2e8930319503683305781378a7dbf building syzkaller on 6972b10616d785401dea17cec890cca8916424a7 testing commit f9be84db09d2e8930319503683305781378a7dbf compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: 5c9c9530ddf40615173bfe58cf4d4f3b31489b4301ea80089b63a5beb77bfb12 run #0: crashed: general protection fault in nf_tables_dump_sets run #1: crashed: general protection fault in nf_tables_dump_sets run #2: crashed: general protection fault in nf_tables_dump_sets run #3: crashed: KASAN: use-after-free Read in nft_table_lookup run #4: crashed: KASAN: use-after-free Read in nft_table_lookup run #5: crashed: KASAN: use-after-free Read in nft_table_lookup run #6: crashed: general protection fault in nf_tables_dump_sets run #7: crashed: KASAN: use-after-free Read in nft_table_lookup run #8: crashed: general protection fault in nf_tables_dump_sets run #9: OK run #10: OK run #11: OK run #12: OK run #13: OK run #14: OK run #15: OK run #16: crashed: KASAN: use-after-free Read in nf_tables_dump_sets run #17: OK run #18: OK run #19: OK testing current HEAD 27151f177827d478508e756c7657273261aaf8a9 testing commit 27151f177827d478508e756c7657273261aaf8a9 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: 16641971386cc7c580a8fadf8a57435c1b4d52fe2d8533bda740de4f5505355e run #0: crashed: KASAN: use-after-free Read in nft_table_lookup run #1: crashed: KASAN: use-after-free Read in nf_tables_dump_sets run #2: crashed: KASAN: use-after-free Read in nft_table_lookup run #3: crashed: KASAN: use-after-free Read in nf_tables_dump_sets run #4: crashed: general protection fault in nf_tables_dump_sets run #5: crashed: KASAN: use-after-free Read in nft_table_lookup run #6: crashed: KASAN: use-after-free Read in nft_table_lookup run #7: crashed: KASAN: use-after-free Read in nf_tables_dump_sets run #8: OK run #9: OK revisions tested: 2, total time: 33m12.842433416s (build: 14m40.786076274s, test: 17m54.873037341s) the crash still happens on HEAD commit msg: Merge tag 'perf-tools-for-v5.15-2021-09-04' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux crash: KASAN: use-after-free Read in nf_tables_dump_sets ================================================================== BUG: KASAN: use-after-free in nf_tables_dump_sets+0x7c8/0xa40 net/netfilter/nf_tables_api.c:3986 Read of size 8 at addr ffff888063688000 by task syz-executor.4/18158 CPU: 0 PID: 18158 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x57/0x7d lib/dump_stack.c:105 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:256 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 nf_tables_dump_sets+0x7c8/0xa40 net/netfilter/nf_tables_api.c:3986 netlink_dump+0x41e/0xaa0 net/netlink/af_netlink.c:2278 __netlink_dump_start+0x570/0x810 net/netlink/af_netlink.c:2383 netlink_dump_start include/linux/netlink.h:258 [inline] nft_netlink_dump_start_rcu+0x54/0x110 net/netfilter/nf_tables_api.c:859 nf_tables_getset+0x5ec/0x800 net/netfilter/nf_tables_api.c:4083 nfnetlink_rcv_msg+0x547/0xf80 net/netfilter/nfnetlink.c:285 netlink_rcv_skb+0x118/0x370 net/netlink/af_netlink.c:2504 nfnetlink_rcv+0x143/0x340 net/netfilter/nfnetlink.c:654 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x42e/0x700 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x704/0xbf0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xab/0xe0 net/socket.c:724 ____sys_sendmsg+0x5bf/0x7a0 net/socket.c:2409 ___sys_sendmsg+0xd3/0x150 net/socket.c:2463 __sys_sendmsg+0xb2/0x140 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc7fcdd5188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 0000000000000000 RSI: 0000000020000d80 RDI: 0000000000000004 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffeec9bfd9f R14: 00007fc7fcdd5300 R15: 0000000000022000 Allocated by task 18158: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa4/0xd0 mm/kasan/common.c:522 nf_tables_newtable+0xb54/0x1c80 net/netfilter/nf_tables_api.c:1112 nfnetlink_rcv_batch+0x1129/0x2500 net/netfilter/nfnetlink.c:513 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] nfnetlink_rcv+0x2bc/0x340 net/netfilter/nfnetlink.c:652 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x42e/0x700 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x704/0xbf0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xab/0xe0 net/socket.c:724 ____sys_sendmsg+0x5bf/0x7a0 net/socket.c:2409 ___sys_sendmsg+0xd3/0x150 net/socket.c:2463 __sys_sendmsg+0xb2/0x140 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 18155: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1628 [inline] slab_free_freelist_hook+0xe3/0x250 mm/slub.c:1653 slab_free mm/slub.c:3213 [inline] kfree+0xe4/0x540 mm/slub.c:4267 __nft_release_table+0xa04/0xe60 net/netfilter/nf_tables_api.c:9603 nft_rcv_nl_event+0x398/0x4e0 net/netfilter/nf_tables_api.c:9645 notifier_call_chain+0x94/0x170 kernel/notifier.c:83 blocking_notifier_call_chain kernel/notifier.c:318 [inline] blocking_notifier_call_chain+0x5d/0x80 kernel/notifier.c:306 netlink_release+0xa32/0x17e0 net/netlink/af_netlink.c:785 __sock_release+0xbb/0x270 net/socket.c:649 sock_close+0xf/0x20 net/socket.c:1314 __fput+0x206/0x8d0 fs/file_table.c:280 task_work_run+0xc0/0x160 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888063688000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes inside of 512-byte region [ffff888063688000, ffff888063688200) The buggy address belongs to the page: page:ffffea00018da200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x63688 head:ffffea00018da200 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff88800fc41c80 raw: 0000000000000000 0000000000100010 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 0xd2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2952, ts 61455689395, free_ts 9812708253 prep_new_page mm/page_alloc.c:2436 [inline] get_page_from_freelist+0xa6f/0x2f50 mm/page_alloc.c:4168 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5390 alloc_slab_page mm/slub.c:1691 [inline] allocate_slab+0x32e/0x4b0 mm/slub.c:1831 new_slab mm/slub.c:1894 [inline] new_slab_objects mm/slub.c:2640 [inline] ___slab_alloc+0x473/0x7b0 mm/slub.c:2803 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2843 slab_alloc_node mm/slub.c:2925 [inline] __kmalloc_node_track_caller+0x2e3/0x360 mm/slub.c:4653 kmalloc_reserve net/core/skbuff.c:355 [inline] __alloc_skb+0x8b/0x280 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1116 [inline] ndisc_alloc_skb+0x12e/0x320 net/ipv6/ndisc.c:420 ndisc_send_ns+0x126/0x770 net/ipv6/ndisc.c:626 addrconf_dad_work+0xa22/0x11a0 net/ipv6/addrconf.c:4127 process_one_work+0x87f/0x1450 kernel/workqueue.c:2297 worker_thread+0x598/0x1040 kernel/workqueue.c:2444 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1346 [inline] free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1397 free_unref_page_prepare mm/page_alloc.c:3332 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3411 free_contig_range+0xa8/0xf0 mm/page_alloc.c:9269 destroy_args+0x7e/0x503 mm/debug_vm_pgtable.c:1016 debug_vm_pgtable+0x1eb8/0x1f3c mm/debug_vm_pgtable.c:1329 do_one_initcall+0xbe/0x440 init/main.c:1287 do_initcall_level init/main.c:1360 [inline] do_initcalls init/main.c:1376 [inline] do_basic_setup init/main.c:1396 [inline] kernel_init_freeable+0x5b2/0x60c init/main.c:1598 kernel_init+0x14/0x120 init/main.c:1490 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Memory state around the buggy address: ffff888063687f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888063687f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888063688000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888063688080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888063688100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================