syzbot


KMSAN: uninit-value in fq_change

Status: fixed on 2023/12/21 01:43
Subsystems: net
[Documentation on labels]
Fix commit: f1a3b283f852 UPSTREAM: net_sched: sch_fq: better validate TCA_FQ_WEIGHTS and TCA_FQ_PRIOMAP
First crash: 117d, last: 111d

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in fq_load_weights net/sched/sch_fq.c:960 [inline]
BUG: KMSAN: uninit-value in fq_change+0x1348/0x2fe0 net/sched/sch_fq.c:1071
 fq_load_weights net/sched/sch_fq.c:960 [inline]
 fq_change+0x1348/0x2fe0 net/sched/sch_fq.c:1071
 fq_init+0x68e/0x780 net/sched/sch_fq.c:1159
 qdisc_create+0x12f3/0x1be0 net/sched/sch_api.c:1326
 tc_modify_qdisc+0x11ef/0x2c20
 rtnetlink_rcv_msg+0x16a6/0x1840 net/core/rtnetlink.c:6558
 netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545
 rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6576
 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
 netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368
 netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2588
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2642
 __sys_sendmsg net/socket.c:2671 [inline]
 __do_sys_sendmsg net/socket.c:2680 [inline]
 __se_sys_sendmsg net/socket.c:2678 [inline]
 __x64_sys_sendmsg+0x307/0x490 net/socket.c:2678
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was created at:
 slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560
 __alloc_skb+0x318/0x740 net/core/skbuff.c:651
 alloc_skb include/linux/skbuff.h:1286 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline]
 netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2588
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2642
 __sys_sendmsg net/socket.c:2671 [inline]
 __do_sys_sendmsg net/socket.c:2680 [inline]
 __se_sys_sendmsg net/socket.c:2678 [inline]
 __x64_sys_sendmsg+0x307/0x490 net/socket.c:2678
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 1 PID: 5001 Comm: syz-executor300 Not tainted 6.6.0-syzkaller-12401-g8f6f76a6a29f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
=====================================================

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/04 04:55 upstream 8f6f76a6a29f 500bfdc4 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce KMSAN: uninit-value in fq_change
2023/11/09 10:56 upstream 6bc986ab839c 4862372a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce KMSAN: uninit-value in fq_change
2023/11/08 14:11 upstream 305230142ae0 83211397 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce KMSAN: uninit-value in fq_change
2023/11/08 14:04 upstream 305230142ae0 83211397 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce KMSAN: uninit-value in fq_change
2023/11/08 09:53 upstream 13d88ac54ddd 83211397 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce KMSAN: uninit-value in fq_change
2023/11/08 09:47 upstream 13d88ac54ddd 83211397 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce KMSAN: uninit-value in fq_change
2023/11/04 03:24 upstream 8f6f76a6a29f 500bfdc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce KMSAN: uninit-value in fq_change
2023/11/04 03:24 upstream 8f6f76a6a29f 500bfdc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce KMSAN: uninit-value in fq_change
* Struck through repros no longer work on HEAD.