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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: 1437d, last: 23h57m
▶ ▼ Discussions (17)
Title Replies (including bot) Last reply
[syzbot] Monthly net report (Oct 2025) 0 (1) 2025/10/16 08:36
[syzbot] Monthly net report (Sep 2025) 0 (1) 2025/09/15 06:54
[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 1211d 1890d 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 844d 2465d 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 888d 2057d 22/29 fixed on 2023/06/08 14:41
upstream KMSAN: uninit-value in ipv6_find_tlv net 7 C 271 929d 2283d 22/29 fixed on 2023/06/08 14:41
upstream KMSAN: uninit-value in ax25cmp (2) hams 7 C 51 1148d 1409d 0/29 closed as invalid on 2022/11/18 11:50
upstream KMSAN: uninit-value in virtqueue_add (3) virt 7 13 1104d 1397d 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 992d 1344d 22/29 fixed on 2023/02/24 13:50
upstream KMSAN: kernel-infoleak in __skb_datagram_iter net 9 68 778d 883d 23/29 fixed on 2023/09/28 17:51
upstream KMSAN: uninit-value in can_send can 7 C 630 1087d 1105d 22/29 fixed on 2023/02/24 13:50
upstream KMSAN: uninit-value in IP6_ECN_decapsulate net 7 C 981 693d 2609d 25/29 fixed on 2023/12/21 03:45
upstream KMSAN: uninit-value in inet_frag_find (2) net 7 2 1401d 1409d 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 1345d 1434d 20/29 fixed on 2022/03/08 16:11
upstream KMSAN: uninit-value in eth_type_trans (2) net 7 C 7842 1h49m 2121d 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 844d 1127d 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 1037d 1127d 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 1132d 1820d 0/29 closed as invalid on 2022/10/12 18:48
upstream KMSAN: uninit-value in br_dev_xmit bridge 7 C 537 1032d 2088d 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 984d 2088d 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 (1903):
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
2025/11/11 17:03 upstream 4427259cc7f7 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/11/08 06:53 upstream da32d155f4a8 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/11/04 20:52 upstream c9cfc122f037 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/11/01 00:01 upstream b909d77359b8 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/31 19:12 upstream d127176862a9 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/30 19:01 upstream e53642b87a4f fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/30 18:50 upstream e53642b87a4f fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/28 03:52 upstream dcb6fa37fd7b fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/28 01:33 upstream dcb6fa37fd7b fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/27 08:34 upstream 4bb1f7e19c4a c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/26 16:42 upstream 72761a7e3122 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/23 22:30 upstream 43e9ad0c55a3 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/21 13:00 upstream 211ddde0823f 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/21 05:16 upstream 211ddde0823f 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/20 12:00 upstream 211ddde0823f 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/20 06:31 upstream d9043c79ba68 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/17 14:10 upstream 98ac9cc4b445 7adf5298 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/17 03:23 upstream 98ac9cc4b445 19568248 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/14 23:07 upstream 9b332cece987 b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/09 07:38 upstream cd5a0afbdf80 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/06 22:06 upstream 9b0d551bcc05 91305dbe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/04 02:57 upstream 9b0d551bcc05 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/10/01 06:49 upstream 50c19e20ed2e 65a0eece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bpf_prog_run_generic_xdp
2025/09/30 12:51 upstream 1896ce8eb6c6 86341da6 .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
2025/11/11 19:40 upstream 4427259cc7f7 4e1406b4 .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
2025/11/11 16:27 upstream 4427259cc7f7 4e1406b4 .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
2025/11/09 06:00 upstream 439fc29dfd3b 4e1406b4 .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
2025/11/08 09:54 upstream 38a2c275c3d3 4e1406b4 .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
2025/11/01 03:06 upstream b909d77359b8 2c50b6a9 .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
2025/10/30 05:30 upstream e53642b87a4f fd2207e7 .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
2025/10/29 21:16 upstream e53642b87a4f fd2207e7 .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
2025/10/27 14:53 upstream dcb6fa37fd7b c0460fcd .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
2025/10/27 13:41 upstream dcb6fa37fd7b c0460fcd .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
2025/10/24 00:30 upstream 43e9ad0c55a3 c0460fcd .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
2025/10/21 06:27 upstream 211ddde0823f 9832ed61 .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
2025/10/21 06:27 upstream 211ddde0823f 9832ed61 .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
2025/10/18 10:26 upstream cf1ea8854e4f 1c8c8cd8 .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
2025/10/17 16:21 upstream 98ac9cc4b445 7adf5298 .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
2025/10/17 08:29 upstream 98ac9cc4b445 19568248 .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
2025/10/15 04:36 upstream 9b332cece987 b6605ba8 .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
2025/10/15 02:24 upstream 9b332cece987 b6605ba8 .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
2025/10/09 09:33 upstream cd5a0afbdf80 7e2882b3 .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
2025/10/04 07:10 upstream 9b0d551bcc05 49379ee0 .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
2025/10/01 02:53 upstream 30d4efb2f5a5 65a0eece .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.