[syzbot] [virt?] [net?] upstream test error: KMSAN: uninit-value in virtnet_poll

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 626737a5791b Merge tag 'pinctrl-v6.10-2' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1373f72e980000
kernel config: https://syzkaller.appspot.com/x/.config?x=12ff58d525e7b8f9
dashboard link: https://syzkaller.appspot.com/bug?extid=35b9a14142dd62084eb9
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b5c2e4152e89/disk-626737a5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4847a4cfa180/vmlinux-626737a5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/18f05d5ddcb1/bzImage-626737a5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+35b9a1...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in receive_mergeable drivers/net/virtio_net.c:1847 [inline]
BUG: KMSAN: uninit-value in receive_buf+0x2620/0x6070 drivers/net/virtio_net.c:1973
virtnet_receive drivers/net/virtio_net.c:2277 [inline]
virtnet_poll+0xd1c/0x23c0 drivers/net/virtio_net.c:2380
__napi_poll+0xe7/0x980 net/core/dev.c:6722
handle_softirqs+0x1ce/0x800 kernel/softirq.c:554
common_interrupt+0x94/0xa0 arch/x86/kernel/irq.c:278
asm_common_interrupt+0x2b/0x40 arch/x86/include/asm/idtentry.h:693
kmsan_get_metadata+0x189/0x1d0
kmsan_get_shadow_origin_ptr+0x4d/0xb0 mm/kmsan/shadow.c:102
get_shadow_origin_ptr mm/kmsan/instrumentation.c:36 [inline]
__msan_metadata_ptr_for_load_8+0x24/0x40 mm/kmsan/instrumentation.c:92
unwind_get_return_address_ptr+0x6a/0x100 arch/x86/kernel/unwind_frame.c:28
update_stack_state+0x206/0x270 arch/x86/kernel/unwind_frame.c:251
unwind_next_frame+0x19a/0x470 arch/x86/kernel/unwind_frame.c:315
arch_stack_walk+0x1ec/0x2d0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0xe0 kernel/stacktrace.c:122
kmsan_save_stack_with_flags mm/kmsan/core.c:74 [inline]
kmsan_internal_poison_memory+0x49/0x90 mm/kmsan/core.c:58
kmsan_slab_alloc+0xdf/0x160 mm/kmsan/hooks.c:68
slab_post_alloc_hook mm/slub.c:3947 [inline]
slab_alloc_node mm/slub.c:4001 [inline]
__do_kmalloc_node mm/slub.c:4121 [inline]
__kmalloc_noprof+0x660/0xf30 mm/slub.c:4135
kmalloc_noprof include/linux/slab.h:664 [inline]
tomoyo_realpath_from_path+0x104/0xaa0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x1ef/0xc50 security/tomoyo/file.c:771
tomoyo_file_open+0x271/0x360 security/tomoyo/tomoyo.c:334
security_file_open+0x9a/0xc60 security/security.c:2962
do_dentry_open+0x5b1/0x22b0 fs/open.c:942
vfs_open+0x49/0x60 fs/open.c:1089
do_open fs/namei.c:3650 [inline]
path_openat+0x4ab0/0x5b70 fs/namei.c:3807
do_filp_open+0x20e/0x590 fs/namei.c:3834
do_sys_openat2+0x1bf/0x2f0 fs/open.c:1405
do_sys_open fs/open.c:1420 [inline]
__do_sys_openat fs/open.c:1436 [inline]
__se_sys_openat fs/open.c:1431 [inline]
__x64_sys_openat+0x2a1/0x310 fs/open.c:1431
x64_sys_call+0x128b/0x3b90 arch/x86/include/generated/asm/syscalls_64.h:258
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:
__alloc_pages_noprof+0x9d6/0xe70 mm/page_alloc.c:4701
alloc_pages_mpol_noprof+0x299/0x990 mm/mempolicy.c:2265
alloc_pages_noprof+0x1bf/0x1e0 mm/mempolicy.c:2336
skb_page_frag_refill+0x2bf/0x7c0 net/core/sock.c:2920
virtnet_rq_alloc+0x43/0xbb0 drivers/net/virtio_net.c:882
add_recvbuf_mergeable drivers/net/virtio_net.c:2128 [inline]
try_fill_recv+0x3f0/0x2f50 drivers/net/virtio_net.c:2173
virtnet_open+0x1cc/0xb00 drivers/net/virtio_net.c:2452
__dev_open+0x546/0x6f0 net/core/dev.c:1472
__dev_change_flags+0x309/0x9a0 net/core/dev.c:8781
dev_change_flags+0x8e/0x1d0 net/core/dev.c:8853
devinet_ioctl+0x13ec/0x22c0 net/ipv4/devinet.c:1177
inet_ioctl+0x4bd/0x6d0 net/ipv4/af_inet.c:1003
sock_do_ioctl+0xb7/0x540 net/socket.c:1222
sock_ioctl+0x727/0xd70 net/socket.c:1341
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0x261/0x450 fs/ioctl.c:893
__x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:893
x64_sys_call+0x18c0/0x3b90 arch/x86/include/generated/asm/syscalls_64.h:17
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: 0 PID: 4794 Comm: rm Not tainted 6.10.0-rc5-syzkaller-00012-g626737a5791b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
=====================================================


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