syzbot


KMSAN: uninit-value in gtp_dev_xmit

Status: fixed on 2024/10/09 09:20
Subsystems: net
[Documentation on labels]
Fix commit: 3a3be7ff9224 gtp: pull network headers in gtp_dev_xmit()
First crash: 125d, last: 125d

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in ipv6_pdp_find drivers/net/gtp.c:220 [inline]
BUG: KMSAN: uninit-value in gtp_build_skb_ip6 drivers/net/gtp.c:1229 [inline]
BUG: KMSAN: uninit-value in gtp_dev_xmit+0x1424/0x2540 drivers/net/gtp.c:1281
 ipv6_pdp_find drivers/net/gtp.c:220 [inline]
 gtp_build_skb_ip6 drivers/net/gtp.c:1229 [inline]
 gtp_dev_xmit+0x1424/0x2540 drivers/net/gtp.c:1281
 __netdev_start_xmit include/linux/netdevice.h:4913 [inline]
 netdev_start_xmit include/linux/netdevice.h:4922 [inline]
 xmit_one net/core/dev.c:3580 [inline]
 dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3596
 __dev_queue_xmit+0x358c/0x5610 net/core/dev.c:4423
 dev_queue_xmit include/linux/netdevice.h:3105 [inline]
 packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3145 [inline]
 packet_sendmsg+0x90e3/0xa3a0 net/packet/af_packet.c:3177
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x30f/0x380 net/socket.c:745
 __sys_sendto+0x685/0x830 net/socket.c:2204
 __do_sys_sendto net/socket.c:2216 [inline]
 __se_sys_sendto net/socket.c:2212 [inline]
 __x64_sys_sendto+0x125/0x1d0 net/socket.c:2212
 x64_sys_call+0x3799/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:45
 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:3994 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4080
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:583
 __alloc_skb+0x363/0x7b0 net/core/skbuff.c:674
 alloc_skb include/linux/skbuff.h:1320 [inline]
 alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6526
 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2815
 packet_alloc_skb net/packet/af_packet.c:2994 [inline]
 packet_snd net/packet/af_packet.c:3088 [inline]
 packet_sendmsg+0x749c/0xa3a0 net/packet/af_packet.c:3177
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x30f/0x380 net/socket.c:745
 __sys_sendto+0x685/0x830 net/socket.c:2204
 __do_sys_sendto net/socket.c:2216 [inline]
 __se_sys_sendto net/socket.c:2212 [inline]
 __x64_sys_sendto+0x125/0x1d0 net/socket.c:2212
 x64_sys_call+0x3799/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:45
 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: 1 UID: 0 PID: 13218 Comm: syz.0.2549 Not tainted 6.11.0-rc1-syzkaller-00043-g94ede2a3e913 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
=====================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/30 07:22 upstream 94ede2a3e913 5187fc86 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in gtp_dev_xmit
2024/07/30 07:14 upstream 94ede2a3e913 5187fc86 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in gtp_dev_xmit
2024/07/30 07:14 upstream 94ede2a3e913 5187fc86 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in gtp_dev_xmit
* Struck through repros no longer work on HEAD.