syzbot


KMSAN: uninit-value in bpf_prog_run_generic_xdp

Status: upstream: reported C repro on 2022/11/18 11:39
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+0e6ddb1ef80986bdfe64@syzkaller.appspotmail.com
First crash: 1356d, last: 17h28m
Discussions (15)
Title Replies (including bot) Last reply
[syzbot] Monthly net report (Aug 2025) 0 (1) 2025/08/14 12:42
[syzbot] Monthly net report (Jul 2025) 0 (1) 2025/07/14 07:23
[PATCH bpf v2 0/2] bpf, xdp: clean adjust_{head,meta} memory when offset < 0 8 (8) 2025/04/04 00:29
[PATCH net v1] net: Fix tuntap uninitialized value 5 (5) 2025/03/31 11:47
[PATCH v2] can: fix skb reference counting in j1939_session_new() 11 (11) 2024/11/29 13:25
[syzbot] KMSAN: uninit-value in bpf_prog_run_generic_xdp 0 (3) 2024/07/01 10:19
[syzbot] Monthly can report (May 2024) 0 (1) 2024/05/31 06:49
[syzbot] Monthly bpf report (Mar 2024) 0 (1) 2024/03/11 10:18
[syzbot] Monthly bpf report (Feb 2024) 0 (1) 2024/02/08 21:48
[syzbot] Monthly can report (Jan 2024) 0 (1) 2024/01/16 07:55
Re: [syzbot] KMSAN: uninit-value in bpf_prog_run_generic_xdp 1 (1) 2023/12/21 11:22
[syzbot] Monthly can report (Dec 2023) 0 (1) 2023/12/02 14:45
[syzbot] Monthly bpf report (Nov 2023) 0 (1) 2023/11/07 04:52
[syzbot] Monthly can report (Nov 2023) 0 (1) 2023/11/01 10:13
[syzbot] Monthly batman report (Oct 2023) 0 (1) 2023/10/09 09:23
Similar bugs (18)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in skb_release_data (3) net 7 C 10 1131d 1809d 0/29 auto-obsoleted due to no activity on 2022/11/17 07:20
upstream KMSAN: uninit-value in hsr_register_frame_in net 7 C 197 764d 2385d 0/29 auto-obsoleted due to no activity on 2024/02/18 18:09
upstream KMSAN: kernel-infoleak in copyout (2) net 17 C 6723 808d 1976d 22/29 fixed on 2023/06/08 14:41
upstream KMSAN: uninit-value in ipv6_find_tlv net 7 C 271 849d 2202d 22/29 fixed on 2023/06/08 14:41
upstream KMSAN: uninit-value in ax25cmp (2) hams 7 C 51 1068d 1328d 0/29 closed as invalid on 2022/11/18 11:50
upstream KMSAN: uninit-value in virtqueue_add (3) virt 7 13 1024d 1316d 0/29 auto-obsoleted due to no activity on 2023/02/12 03:53
upstream KMSAN: kernel-infoleak in _copy_to_iter (7) net 23 C 138977 911d 1264d 22/29 fixed on 2023/02/24 13:50
upstream KMSAN: kernel-infoleak in __skb_datagram_iter net 9 68 697d 802d 23/29 fixed on 2023/09/28 17:51
upstream KMSAN: uninit-value in can_send can 7 C 630 1006d 1024d 22/29 fixed on 2023/02/24 13:50
upstream KMSAN: uninit-value in IP6_ECN_decapsulate net 7 C 981 613d 2529d 25/29 fixed on 2023/12/21 03:45
upstream KMSAN: uninit-value in inet_frag_find (2) net 7 2 1320d 1328d 0/29 auto-closed as invalid on 2022/04/11 17:13
upstream KMSAN: kernel-infoleak in _copy_to_iter (6) net 9 C 748 1264d 1353d 20/29 fixed on 2022/03/08 16:11
upstream KMSAN: uninit-value in eth_type_trans (2) net 7 C 7510 11h05m 2040d 0/29 upstream: reported C repro on 2020/01/22 16:47
upstream KMSAN: uninit-value in hsr_fill_frame_info (2) net 7 C 65 763d 1046d 0/29 auto-obsoleted due to no activity on 2023/10/30 13:38
upstream KMSAN: uninit-value in erspan_build_header net 7 40 956d 1046d 0/29 auto-obsoleted due to no activity on 2023/05/10 10:26
upstream KMSAN: uninit-value in ip_tunnel_xmit (3) net 7 C 1516 1052d 1740d 0/29 closed as invalid on 2022/10/12 18:48
upstream KMSAN: uninit-value in br_dev_xmit bridge 7 C 537 951d 2008d 0/29 auto-obsoleted due to no activity on 2023/05/15 13:28
upstream KMSAN: uninit-value in batadv_get_vid batman 7 C 1947 903d 2008d 0/29 auto-obsoleted due to no activity on 2023/07/23 05:56
Last patch testing requests (5)
Created Duration User Patch Repo Result
2025/06/06 14:17 25m retest repro upstream report log
2025/06/06 14:17 25m retest repro upstream report log
2025/06/06 14:17 29m retest repro upstream OK log
2024/07/03 03:13 33m retest repro upstream error
2024/07/01 10:19 19m wojciech.gladysz@infogain.com patch https://linux.googlesource.com/linux/kernel/git/torvalds/linux e478cf26c556e4ab572ab0ab2306c986901dcd61 report log

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in bpf_prog_run_generic_xdp+0x190a/0x1f20 net/core/dev.c:5154
 bpf_prog_run_generic_xdp+0x190a/0x1f20 net/core/dev.c:5154
 netif_receive_generic_xdp net/core/dev.c:5236 [inline]
 do_xdp_generic+0xc0d/0x15a0 net/core/dev.c:5298
 tun_get_user+0x4952/0x6e50 drivers/net/tun.c:1929
 tun_chr_write_iter+0x3ac/0x5d0 drivers/net/tun.c:2053
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xb34/0x1540 fs/read_write.c:679
 ksys_write+0x240/0x4b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:739
 x64_sys_call+0x3161/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 pskb_expand_head+0x33a/0x1b70 net/core/skbuff.c:2283
 netif_skb_check_for_xdp net/core/dev.c:5199 [inline]
 netif_receive_generic_xdp net/core/dev.c:5230 [inline]
 do_xdp_generic+0x9e3/0x15a0 net/core/dev.c:5298
 tun_get_user+0x4952/0x6e50 drivers/net/tun.c:1929
 tun_chr_write_iter+0x3ac/0x5d0 drivers/net/tun.c:2053
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xb34/0x1540 fs/read_write.c:679
 ksys_write+0x240/0x4b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:739
 x64_sys_call+0x3161/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4121 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 __do_kmalloc_node mm/slub.c:4293 [inline]
 __kmalloc_node_track_caller_noprof+0x945/0x1240 mm/slub.c:4313
 kmalloc_reserve+0x23e/0x4a0 net/core/skbuff.c:609
 __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1331 [inline]
 alloc_skb_with_frags+0xc8/0xd00 net/core/skbuff.c:6612
 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2897
 tun_alloc_skb drivers/net/tun.c:1526 [inline]
 tun_get_user+0x1c6d/0x6e50 drivers/net/tun.c:1851
 tun_chr_write_iter+0x3ac/0x5d0 drivers/net/tun.c:2053
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xb34/0x1540 fs/read_write.c:679
 ksys_write+0x240/0x4b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:739
 x64_sys_call+0x3161/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 5786 Comm: syz-executor617 Not tainted 6.14.0-rc2-syzkaller-00281-g496659003dac #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
=====================================================

Crashes (1708):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/16 06:41 upstream 496659003dac 40a34ec9 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2024/11/06 10:23 upstream 2e1b3cc9d7f7 3a465482 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/23 13:04 upstream 6debb6904172 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/23 13:04 upstream 6debb6904172 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/23 01:00 upstream a2e94e80790b bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/22 07:07 upstream 3957a5720157 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/21 18:26 upstream 32b7144f806e 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/20 11:38 upstream b19a97d57c15 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/17 14:21 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/11 08:44 upstream 8f5ae30d69d7 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/10 03:06 upstream c30a13538d9f 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/10 03:05 upstream c30a13538d9f 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/09 22:43 upstream c30a13538d9f 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/09 18:11 upstream c30a13538d9f 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/08 06:15 upstream 6e64f4580381 6a893178 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/06 21:03 upstream a530a36bb548 4bd24a3e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/06 02:00 upstream 5998f2bca43e 904e669c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/05 20:11 upstream 5998f2bca43e 904e669c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/03 00:36 upstream 89748acdf226 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/07/28 18:43 upstream 038d61fd6422 c4a95487 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/07/28 15:28 upstream 038d61fd6422 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/07/27 10:05 upstream 302f88ff3584 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/07/26 13:28 upstream 5f33ebd2018c fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/07/26 04:57 upstream 327579671a9b fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/07/25 17:01 upstream 2942242dde89 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/07/22 16:28 upstream 89be9a83ccf1 1555463b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2024/03/16 16:19 upstream 66a27abac311 d615901c .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/23 15:44 upstream 6debb6904172 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/22 10:13 upstream 3957a5720157 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/16 12:50 upstream dfd4b508c8c6 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/14 04:09 upstream 91325f31afc1 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/14 03:59 upstream 91325f31afc1 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/14 02:32 upstream 91325f31afc1 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/12 19:59 upstream 53e760d89498 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/10 06:35 upstream 561c80369df0 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/09 03:50 upstream 37816488247d 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/08 21:30 upstream 37816488247d 987b750d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/07 21:57 upstream d2eedaa3909b 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/07 06:03 upstream d2eedaa3909b 4bd24a3e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/07 03:35 upstream d2eedaa3909b 4bd24a3e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/05 23:34 upstream d2eedaa3909b 904e669c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/05 20:41 upstream d2eedaa3909b 904e669c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/03 20:51 upstream 186f3edfdd41 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/08/03 07:13 upstream eacf91b0c78a 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/07/27 11:06 upstream 513fc69f8fc7 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/07/26 17:54 upstream 5f33ebd2018c fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/07/25 22:23 upstream 327579671a9b fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2023/12/16 05:36 upstream 3bd7d7488169 3222d10c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386 KMSAN: uninit-value in bpf_prog_run_generic_xdp
2022/11/15 12:56 https://github.com/google/kmsan.git master cb231e2f67ec 97de9cfc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386 KMSAN: uninit-value in bpf_prog_run_generic_xdp
2022/01/03 16:49 https://github.com/google/kmsan.git master 81c325bbf94e 4a3f34f2 .config console log report info ci-upstream-kmsan-gce-386 KMSAN: uninit-value in bpf_prog_run_generic_xdp
2021/12/06 12:45 https://github.com/google/kmsan.git master cdfb223e7e63 579a8754 .config console log report info ci-upstream-kmsan-gce-386 KMSAN: uninit-value in bpf_prog_run_generic_xdp
* Struck through repros no longer work on HEAD.