syzbot


KMSAN: kernel-infoleak in __skb_datagram_iter (4)

Status: fixed on 2026/01/07 12:29
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+0c85cae3350b7d486aee@syzkaller.appspotmail.com
Fix commit: 62b656e43eae net: sched: act_connmark: initialize struct tc_ife to fix kernel leak ce50039be49e net: sched: act_ife: initialize struct tc_ife to fix KMSAN kernel-infoleak
First crash: 599d, last: 6d11h
Discussions (6)
Title Replies (including bot) Last reply
[PATCH v4 net 0/2] net: sched: initialize struct tc_ife to fix kernel-infoleak 12 (12) 2025/12/15 16:27
[PATCH v3 0/2] net: sched: initialize struct tc_ife to fix kernel-infoleak 7 (7) 2025/11/08 01:26
[PATCH v3 0/2] net: sched: initialize struct tc_ife to fix kernel-infoleak 1 (1) 2025/11/06 19:28
[PATCH v2 0/2] net: sched: act_ife: initialize struct tc_ife to fix KMSAN kernel-infoleak 9 (9) 2025/11/06 13:31
[syzbot] [net?] KMSAN: kernel-infoleak in __skb_datagram_iter (4) 1 (6) 2025/11/05 09:03
[PATCH] net: sched: act_ife: initialize struct tc_ife to fix KMSAN kernel-infoleak 5 (5) 2025/10/31 16:00
Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: kernel-infoleak in __skb_datagram_iter (2) net 19 C 126 659d 711d 25/29 fixed on 2024/03/25 23:45
upstream KMSAN: kernel-infoleak in copyout (2) net 17 C 6723 950d 2119d 22/29 fixed on 2023/06/08 14:41
upstream KMSAN: kernel-infoleak in __skb_datagram_iter (5) net 9 4 3d15h 5d09h 22/29 upstream: reported on 2026/01/08 10:16
upstream KMSAN: kernel-infoleak in __skb_datagram_iter (3) net 9 C 25 603d 657d 25/29 fixed on 2024/05/23 00:06
upstream KMSAN: kernel-infoleak in __skb_datagram_iter net 9 68 840d 945d 23/29 fixed on 2023/09/28 17:51
android-5-15 KASAN: use-after-free Read in __skb_datagram_iter origin:upstream 19 C done 1 761d 792d 0/2 auto-obsoleted due to no activity on 2024/03/22 20:57
upstream KASAN: use-after-free Read in __skb_datagram_iter net 19 431 1715d 1722d 0/29 auto-closed as invalid on 2021/07/03 04:24
Last patch testing requests (3)
Created Duration User Patch Repo Result
2025/11/05 09:03 27m vnranganath.20@gmail.com patch upstream OK log
2025/10/31 09:49 45m vnranganath.20@gmail.com patch upstream OK log
2024/11/06 18:09 9m edumazet@google.com patch upstream error

Sample crash report:
=====================================================
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in copy_to_user_iter lib/iov_iter.c:24 [inline]
BUG: KMSAN: kernel-infoleak in iterate_ubuf include/linux/iov_iter.h:30 [inline]
BUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:300 [inline]
BUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:328 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x2f3/0x2b30 lib/iov_iter.c:185
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 copy_to_user_iter lib/iov_iter.c:24 [inline]
 iterate_ubuf include/linux/iov_iter.h:30 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:300 [inline]
 iterate_and_advance include/linux/iov_iter.h:328 [inline]
 _copy_to_iter+0x2f3/0x2b30 lib/iov_iter.c:185
 copy_to_iter include/linux/uio.h:211 [inline]
 simple_copy_to_iter net/core/datagram.c:524 [inline]
 __skb_datagram_iter+0x18d/0x1190 net/core/datagram.c:401
 skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:538
 skb_copy_datagram_msg include/linux/skbuff.h:4076 [inline]
 netlink_recvmsg+0x432/0x1610 net/netlink/af_netlink.c:1958
 sock_recvmsg_nosec net/socket.c:1051 [inline]
 sock_recvmsg+0x2c4/0x340 net/socket.c:1073
 sock_read_iter+0x32d/0x3c0 net/socket.c:1143
 io_iter_do_read io_uring/rw.c:771 [inline]
 __io_read+0x8d2/0x20f0 io_uring/rw.c:865
 io_read+0x3e/0xf0 io_uring/rw.c:943
 io_issue_sqe+0x429/0x22c0 io_uring/io_uring.c:1739
 io_queue_sqe io_uring/io_uring.c:1953 [inline]
 io_req_task_submit+0x104/0x1e0 io_uring/io_uring.c:1373
 io_poll_task_func+0x12e5/0x1620
 io_handle_tw_list+0x23a/0x5c0 io_uring/io_uring.c:1063
 tctx_task_work_run+0xf8/0x3d0 io_uring/io_uring.c:1135
 tctx_task_work+0x6d/0xc0 io_uring/io_uring.c:1153
 task_work_run+0x268/0x310 kernel/task_work.c:239
 ptrace_notify+0x304/0x320 kernel/signal.c:2403
 ptrace_report_syscall include/linux/ptrace.h:415 [inline]
 ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
 syscall_exit_work+0x14e/0x3e0 kernel/entry/common.c:173
 syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
 syscall_exit_to_user_mode+0x13b/0x170 kernel/entry/common.c:218
 do_syscall_64+0xda/0x1e0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 pskb_expand_head+0x305/0x1a60 net/core/skbuff.c:2283
 netlink_trim+0x2c2/0x330 net/netlink/af_netlink.c:1313
 netlink_unicast+0x9f/0x1260 net/netlink/af_netlink.c:1347
 nlmsg_unicast include/net/netlink.h:1158 [inline]
 nlmsg_notify+0x21d/0x2f0 net/netlink/af_netlink.c:2602
 rtnetlink_send+0x73/0x90 net/core/rtnetlink.c:770
 rtnetlink_maybe_send include/linux/rtnetlink.h:18 [inline]
 tcf_add_notify net/sched/act_api.c:2068 [inline]
 tcf_action_add net/sched/act_api.c:2091 [inline]
 tc_ctl_action+0x146e/0x19d0 net/sched/act_api.c:2139
 rtnetlink_rcv_msg+0x12fc/0x1410 net/core/rtnetlink.c:6675
 netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2551
 rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6693
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0x30f/0x380 net/socket.c:744
 ____sys_sendmsg+0x877/0xb60 net/socket.c:2607
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2661
 __sys_sendmsg net/socket.c:2690 [inline]
 __do_sys_sendmsg net/socket.c:2699 [inline]
 __se_sys_sendmsg net/socket.c:2697 [inline]
 __x64_sys_sendmsg+0x300/0x4a0 net/socket.c:2697
 x64_sys_call+0x2da0/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:47
 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:
 __nla_put lib/nlattr.c:1041 [inline]
 nla_put+0x1c6/0x230 lib/nlattr.c:1099
 tcf_ife_dump+0x250/0x10b0 net/sched/act_ife.c:660
 tcf_action_dump_old net/sched/act_api.c:1190 [inline]
 tcf_action_dump_1+0x85e/0x970 net/sched/act_api.c:1226
 tcf_action_dump+0x1fd/0x460 net/sched/act_api.c:1250
 tca_get_fill+0x519/0x7a0 net/sched/act_api.c:1648
 tcf_add_notify_msg net/sched/act_api.c:2043 [inline]
 tcf_add_notify net/sched/act_api.c:2062 [inline]
 tcf_action_add net/sched/act_api.c:2091 [inline]
 tc_ctl_action+0x1365/0x19d0 net/sched/act_api.c:2139
 rtnetlink_rcv_msg+0x12fc/0x1410 net/core/rtnetlink.c:6675
 netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2551
 rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6693
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0x30f/0x380 net/socket.c:744
 ____sys_sendmsg+0x877/0xb60 net/socket.c:2607
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2661
 __sys_sendmsg net/socket.c:2690 [inline]
 __do_sys_sendmsg net/socket.c:2699 [inline]
 __se_sys_sendmsg net/socket.c:2697 [inline]
 __x64_sys_sendmsg+0x300/0x4a0 net/socket.c:2697
 x64_sys_call+0x2da0/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:47
 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

Local variable opt created at:
 tcf_ife_dump+0xab/0x10b0 net/sched/act_ife.c:647
 tcf_action_dump_old net/sched/act_api.c:1190 [inline]
 tcf_action_dump_1+0x85e/0x970 net/sched/act_api.c:1226

Bytes 158-159 of 216 are uninitialized
Memory access of size 216 starts at ffff88811980e280

CPU: 1 UID: 0 PID: 5791 Comm: syz-executor190 Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
=====================================================

Crashes (1050):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/06 17:57 upstream 2e1b3cc9d7f7 3a465482 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2026/01/06 17:35 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2026/01/01 18:35 upstream b69053dd3ffb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/25 18:11 upstream ccd1cdca5cd4 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/25 07:10 upstream ccd1cdca5cd4 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/24 03:02 upstream b927546677c8 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/22 08:31 upstream 765b233a9b94 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/15 23:27 upstream 8f0b4cce4481 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/08 23:16 upstream c2f2b01b74be d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/06 15:03 upstream 416f99c3b16f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/06 02:07 upstream d1d36025a617 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/03 08:03 upstream 44fc84337b6e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/02 15:46 upstream 4a26e7032d7d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/11/29 14:03 upstream 19eef1d98eed d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in __skb_datagram_iter
2026/01/07 07:50 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2026/01/05 16:06 upstream 3609fa95fb0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2026/01/01 22:24 upstream b69053dd3ffb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2026/01/01 07:48 upstream 349bd28a86f2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/31 20:24 upstream c8ebd433459b d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/30 01:00 upstream 8640b74557fc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/29 21:58 upstream 7839932417dd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/27 08:20 upstream 3f0e9c8cefa9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/25 10:05 upstream ccd1cdca5cd4 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/23 17:59 upstream b927546677c8 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/22 02:51 upstream 765b233a9b94 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/21 20:46 upstream 9094662f6707 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/21 07:57 upstream d8ba32c5a460 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/18 20:20 upstream ea1013c15392 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/12 20:24 upstream 187d0801404f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/11 14:53 upstream d358e5254674 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/09 20:19 upstream cb015814f8b6 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/05 09:00 upstream 2aa680df6806 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/04 08:38 upstream 559e608c4655 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/04 04:32 upstream 3f9f0252130e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/03 18:49 upstream 3f9f0252130e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/03 15:18 upstream 619f4edc8d4f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/12/03 12:07 upstream 619f4edc8d4f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/11/30 03:46 upstream 6bda50f4333f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/11/29 20:35 upstream 19eef1d98eed d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/11/29 18:45 upstream 19eef1d98eed d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/11/29 17:41 upstream 19eef1d98eed d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/11/29 16:40 upstream 19eef1d98eed d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/11/29 07:18 upstream 6cf62f0174de d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/11/25 12:49 upstream ac3fd01e4c1e 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/11/25 06:08 upstream ac3fd01e4c1e 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/11/25 05:06 upstream ac3fd01e4c1e 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2024/05/24 04:59 upstream 101b7a97143a 8f98448e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak in __skb_datagram_iter
2025/10/31 22:00 upstream b909d77359b8 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: kernel-infoleak-after-free in __skb_datagram_iter
* Struck through repros no longer work on HEAD.