syzbot


KMSAN: uninit-value in ib_nl_handle_ip_res_resp

Status: upstream: reported C repro on 2025/09/30 20:29
Subsystems: rdma
[Documentation on labels]
Reported-by: syzbot+938fcd548c303fe33c1a@syzkaller.appspotmail.com
First crash: 48d, last: 4d14h
Discussions (3)
Title Replies (including bot) Last reply
[PATCH v2] RDMA/core: Check for missing DGID attribute in ib_nl_is_good_ip_resp() 2 (2) 2025/11/09 00:22
[PATCH] RDMA/core: Fix uninitialized gid in ib_nl_process_good_ip_rsep() 8 (8) 2025/11/08 03:48
[syzbot] [rdma?] KMSAN: uninit-value in ib_nl_handle_ip_res_resp 3 (10) 2025/11/07 22:53
Last patch testing requests (6)
Created Duration User Patch Repo Result
2025/11/13 01:05 23m retest repro upstream report log
2025/11/07 22:53 27m kriish.sharma2006@gmail.com patch upstream OK log
2025/11/07 20:11 1h33m kriish.sharma2006@gmail.com patch upstream OK log
2025/11/07 20:06 34m kriish.sharma2006@gmail.com patch upstream error
2025/11/06 19:45 31m kriish.sharma2006@gmail.com patch upstream OK log
2025/11/06 19:28 23m kriish.sharma2006@gmail.com https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ 566771afc7a8 report log

Sample crash report:
netlink: 8 bytes leftover after parsing attributes in process `syz.0.18'.
=====================================================
BUG: KMSAN: uninit-value in hex_byte_pack include/linux/hex.h:13 [inline]
BUG: KMSAN: uninit-value in ip6_string+0xef4/0x13a0 lib/vsprintf.c:1490
 hex_byte_pack include/linux/hex.h:13 [inline]
 ip6_string+0xef4/0x13a0 lib/vsprintf.c:1490
 ip6_addr_string+0x18a/0x3e0 lib/vsprintf.c:1509
 ip_addr_string+0x245/0xee0 lib/vsprintf.c:1633
 pointer+0xc09/0x1bd0 lib/vsprintf.c:2542
 vsnprintf+0xf8a/0x1bd0 lib/vsprintf.c:2930
 vprintk_store+0x3ae/0x1530 kernel/printk/printk.c:2252
 vprintk_emit+0x21a/0xb60 kernel/printk/printk.c:2399
 vprintk_default+0x3f/0x50 kernel/printk/printk.c:2438
 vprintk+0x36/0x50 kernel/printk/printk_safe.c:82
 _printk+0x17e/0x1b0 kernel/printk/printk.c:2448
 ib_nl_process_good_ip_rsep drivers/infiniband/core/addr.c:128 [inline]
 ib_nl_handle_ip_res_resp+0x963/0x9d0 drivers/infiniband/core/addr.c:141
 rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline]
 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
 rdma_nl_rcv+0xefa/0x11c0 drivers/infiniband/core/netlink.c:259
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0xf04/0x12b0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x10b3/0x1250 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x333/0x3d0 net/socket.c:742
 ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2630
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2684
 __sys_sendmsg net/socket.c:2716 [inline]
 __do_sys_sendmsg net/socket.c:2721 [inline]
 __se_sys_sendmsg net/socket.c:2719 [inline]
 __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2719
 x64_sys_call+0x1dfd/0x3e30 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable gid.i created at:
 ib_nl_process_good_ip_rsep drivers/infiniband/core/addr.c:102 [inline]
 ib_nl_handle_ip_res_resp+0x254/0x9d0 drivers/infiniband/core/addr.c:141
 rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline]
 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
 rdma_nl_rcv+0xefa/0x11c0 drivers/infiniband/core/netlink.c:259

CPU: 0 UID: 0 PID: 6093 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
=====================================================

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/25 16:40 upstream 566771afc7a8 c0460fcd .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ib_nl_handle_ip_res_resp
2025/10/29 18:13 upstream e53642b87a4f fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ib_nl_handle_ip_res_resp
2025/10/25 15:16 upstream 566771afc7a8 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ib_nl_handle_ip_res_resp
2025/10/26 03:53 upstream 72761a7e3122 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in ib_nl_handle_ip_res_resp
2025/10/26 03:52 upstream 72761a7e3122 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in ib_nl_handle_ip_res_resp
2025/09/30 11:50 upstream 1896ce8eb6c6 86341da6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in ib_nl_handle_ip_res_resp
2025/09/30 09:38 upstream 1896ce8eb6c6 86341da6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in ib_nl_handle_ip_res_resp
* Struck through repros no longer work on HEAD.