Hello, syzbot found the following crash on: HEAD commit: 9535d09e page_alloc: drop a call to kmsan_split_page() git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=105fa39be00000 kernel config: https://syzkaller.appspot.com/x/.config?x=a5915107b3106aaa dashboard link: https://syzkaller.appspot.com/bug?extid=ae94def68efda6a4be52 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17314f58100000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+ae94def68efda6a4be52@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline] BUG: KMSAN: uninit-value in __fswab32 include/uapi/linux/swab.h:60 [inline] BUG: KMSAN: uninit-value in __swab32p include/uapi/linux/swab.h:189 [inline] BUG: KMSAN: uninit-value in __be32_to_cpup include/uapi/linux/byteorder/little_endian.h:82 [inline] BUG: KMSAN: uninit-value in get_unaligned_be32 include/linux/unaligned/access_ok.h:30 [inline] BUG: KMSAN: uninit-value in ____bpf_skb_load_helper_32 net/core/filter.c:246 [inline] BUG: KMSAN: uninit-value in bpf_skb_load_helper_32+0x18b/0x2d0 net/core/filter.c:232 CPU: 0 PID: 10091 Comm: syz-executor.0 Not tainted 5.6.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline] __fswab32 include/uapi/linux/swab.h:60 [inline] __swab32p include/uapi/linux/swab.h:189 [inline] __be32_to_cpup include/uapi/linux/byteorder/little_endian.h:82 [inline] get_unaligned_be32 include/linux/unaligned/access_ok.h:30 [inline] ____bpf_skb_load_helper_32 net/core/filter.c:246 [inline] bpf_skb_load_helper_32+0x18b/0x2d0 net/core/filter.c:232 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82 slab_alloc_node mm/slub.c:2801 [inline] __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4420 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1081 [inline] netlink_dump+0x26b/0x1ab0 net/netlink/af_netlink.c:2219 netlink_recvmsg+0xe88/0x1910 net/netlink/af_netlink.c:2001 ____sys_recvmsg+0x1173/0x1240 net/socket.c:886 ___sys_recvmsg net/socket.c:2610 [inline] do_recvmmsg+0x6f3/0x1eb0 net/socket.c:2708 __sys_recvmmsg net/socket.c:2789 [inline] __do_sys_recvmmsg net/socket.c:2810 [inline] __se_sys_recvmmsg+0x25d/0x350 net/socket.c:2803 __x64_sys_recvmmsg+0x62/0x80 net/socket.c:2803 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ===================================================== --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches
