syzbot

 sign-in | mailing list | source | docs
🐞 Open [1590]
≡ Subsystems
🐞 Fixed [6364]
🐞 Invalid [16225]
⬇ Missing Backports [194]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

KASAN: slab-use-after-free Read in consume_skb

Status: closed as invalid on 2023/10/04 10:50
Subsystems: net bpf
[Documentation on labels]
First crash: 672d, last: 671d
Cause bisection: failed (error log, bisect log)
  
▶ ▼ Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: use-after-free Read in consume_skb origin:lts C 73 2d02h 657d 0/2 upstream: reported C repro on 2023/09/21 02:29
android-6-1 KASAN: use-after-free Read in consume_skb C error done 4 609d 668d 0/2 auto-obsoleted due to no activity on 2024/02/15 15:09
linux-5.15 KASAN: use-after-free Read in consume_skb origin:lts-only C done 6 34d 333d 0/3 upstream: reported C repro on 2024/08/09 08:33
upstream KASAN: use-after-free Read in consume_skb bpf net C done inconclusive 33 1088d 1367d 0/29 closed as invalid on 2022/10/12 18:37
▶ ▼ Last patch testing requests (5)
Created Duration User Patch Repo Result
2023/10/04 09:55 35m nogikh@google.com net OK log
2023/09/20 08:54 23m retest repro net-next OK log
2023/09/20 08:54 23m retest repro net OK log
2023/09/20 08:54 22m retest repro net OK log
2023/09/20 08:54 32m retest repro net-next OK log

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
BUG: KASAN: slab-use-after-free in refcount_read include/linux/refcount.h:147 [inline]
BUG: KASAN: slab-use-after-free in skb_unref include/linux/skbuff.h:1217 [inline]
BUG: KASAN: slab-use-after-free in consume_skb+0x32/0x170 net/core/skbuff.c:1279
Read of size 4 at addr ffff8880733c5c24 by task kworker/1:0/22

CPU: 1 PID: 22 Comm: kworker/1:0 Not tainted 6.5.0-syzkaller-04028-gd3287e4038ca #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Workqueue: events sk_psock_destroy
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:475
 kasan_report+0xda/0x110 mm/kasan/report.c:588
 check_region_inline mm/kasan/generic.c:181 [inline]
 kasan_check_range+0xef/0x190 mm/kasan/generic.c:187
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
 refcount_read include/linux/refcount.h:147 [inline]
 skb_unref include/linux/skbuff.h:1217 [inline]
 consume_skb+0x32/0x170 net/core/skbuff.c:1279
 __sk_msg_free+0x230/0x380 net/core/skmsg.c:206
 sk_msg_free net/core/skmsg.c:219 [inline]
 __sk_psock_purge_ingress_msg net/core/skmsg.c:770 [inline]
 __sk_psock_zap_ingress net/core/skmsg.c:783 [inline]
 sk_psock_destroy+0x335/0xa50 net/core/skmsg.c:815
 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600
 worker_thread+0x687/0x1110 kernel/workqueue.c:2751
 kthread+0x33a/0x430 kernel/kthread.c:389
 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>

Allocated by task 5044:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:186 [inline]
 slab_post_alloc_hook mm/slab.h:762 [inline]
 slab_alloc_node mm/slub.c:3470 [inline]
 kmem_cache_alloc_node+0x185/0x3f0 mm/slub.c:3515
 __alloc_skb+0x287/0x330 net/core/skbuff.c:640
 alloc_skb include/linux/skbuff.h:1286 [inline]
 alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6313
 sock_alloc_send_pskb+0x7e4/0x970 net/core/sock.c:2795
 unix_dgram_sendmsg+0x455/0x1c30 net/unix/af_unix.c:1953
 sock_sendmsg_nosec net/socket.c:728 [inline]
 sock_sendmsg+0xd9/0x180 net/socket.c:751
 ____sys_sendmsg+0x2ac/0x940 net/socket.c:2539
 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2593
 __sys_sendmmsg+0x1a1/0x450 net/socket.c:2679
 __do_sys_sendmmsg net/socket.c:2708 [inline]
 __se_sys_sendmmsg net/socket.c:2705 [inline]
 __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2705
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 22:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x15e/0x1b0 mm/kasan/common.c:200
 kasan_slab_free include/linux/kasan.h:162 [inline]
 slab_free_hook mm/slub.c:1792 [inline]
 slab_free_freelist_hook+0x10b/0x1e0 mm/slub.c:1818
 slab_free mm/slub.c:3801 [inline]
 kmem_cache_free+0xf0/0x490 mm/slub.c:3823
 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:1010
 __kfree_skb net/core/skbuff.c:1068 [inline]
 kfree_skb_reason+0x10e/0x210 net/core/skbuff.c:1103
 kfree_skb include/linux/skbuff.h:1234 [inline]
 sock_drop include/linux/skmsg.h:307 [inline]
 __sk_psock_zap_ingress net/core/skmsg.c:781 [inline]
 sk_psock_destroy+0x18d/0xa50 net/core/skmsg.c:815
 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600
 worker_thread+0x687/0x1110 kernel/workqueue.c:2751
 kthread+0x33a/0x430 kernel/kthread.c:389
 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

The buggy address belongs to the object at ffff8880733c5b40
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 228 bytes inside of
 freed 240-byte region [ffff8880733c5b40, ffff8880733c5c30)

The buggy address belongs to the physical page:
page:ffffea0001ccf140 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x733c5
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000200 ffff888019660500 dead000000000122 0000000000000000
raw: 0000000000000000 00000000000c000c 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 0x12820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 5038, tgid 5038 (strace-static-x), ts 76027238060, free_ts 69351215114
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1570
 prep_new_page mm/page_alloc.c:1577 [inline]
 get_page_from_freelist+0x10a9/0x31e0 mm/page_alloc.c:3221
 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4477
 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298
 alloc_slab_page mm/slub.c:1862 [inline]
 allocate_slab+0x24e/0x380 mm/slub.c:2009
 new_slab mm/slub.c:2062 [inline]
 ___slab_alloc+0x8bc/0x1570 mm/slub.c:3215
 __kmem_cache_alloc_bulk mm/slub.c:3966 [inline]
 kmem_cache_alloc_bulk+0x25a/0x7c0 mm/slub.c:4041
 napi_skb_cache_get+0xf7/0x190 net/core/skbuff.c:330
 __napi_build_skb+0x14/0x50 net/core/skbuff.c:509
 __napi_alloc_skb+0x3a7/0x6f0 net/core/skbuff.c:828
 napi_alloc_skb include/linux/skbuff.h:3282 [inline]
 page_to_skb+0x150/0xac0 drivers/net/virtio_net.c:526
 receive_mergeable drivers/net/virtio_net.c:1487 [inline]
 receive_buf+0x11c0/0x52d0 drivers/net/virtio_net.c:1608
 virtnet_receive drivers/net/virtio_net.c:1906 [inline]
 virtnet_poll+0x772/0x1530 drivers/net/virtio_net.c:1978
 __napi_poll.constprop.0+0xb4/0x530 net/core/dev.c:6527
 napi_poll net/core/dev.c:6594 [inline]
 net_rx_action+0x956/0xe90 net/core/dev.c:6727
 __do_softirq+0x218/0x965 kernel/softirq.c:553
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1161 [inline]
 free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2348
 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2443
 __folio_put_small mm/swap.c:106 [inline]
 __folio_put+0xc5/0x140 mm/swap.c:129
 folio_put include/linux/mm.h:1440 [inline]
 put_page include/linux/mm.h:1509 [inline]
 anon_pipe_buf_release+0x3fa/0x4b0 fs/pipe.c:138
 pipe_buf_release include/linux/pipe_fs_i.h:203 [inline]
 pipe_read+0x635/0x1270 fs/pipe.c:324
 call_read_iter include/linux/fs.h:1979 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x7ef/0x930 fs/read_write.c:470
 ksys_read+0x1f0/0x250 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff8880733c5b00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
 ffff8880733c5b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880733c5c00: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff8880733c5c80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880733c5d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/09/06 05:49 net d3287e4038ca 8bc9053e .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce KASAN: slab-use-after-free Read in consume_skb
2023/09/05 15:31 net 2861f09c1112 8bc9053e .config strace log report syz C ci-upstream-net-this-kasan-gce KASAN: slab-use-after-free Read in consume_skb
2023/09/05 19:39 net-next bd6c11bc43c4 8bc9053e .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in consume_skb
2023/09/05 13:35 net-next bd6c11bc43c4 8bc9053e .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in consume_skb
2023/09/05 13:05 net 2861f09c1112 8bc9053e .config console log report info ci-upstream-net-this-kasan-gce KASAN: slab-use-after-free Read in consume_skb
2023/09/05 13:00 net-next bd6c11bc43c4 8bc9053e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in consume_skb
* Struck through repros no longer work on HEAD.