Hello, syzbot found the following crash on: HEAD commit: 788a0249 Merge tag 'arc-5.2-rc4' of git://git.kernel.org/p.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15dc9ea6a00000 kernel config: https://syzkaller.appspot.com/x/.config?x=d5c73825cbdc7326 dashboard link: https://syzkaller.appspot.com/bug?extid=0789f0c7e45efd7bb643 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10b31761a00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=124892c1a00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+0789f0c7e45efd7bb643 at syzkaller.appspotmail.com udit: type=1400 audit(1559768703.229:36): avc: denied { map } for pid=7116 comm="syz-executor330" path="/root/syz-executor330334897" dev="sda1" ino=16461 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 executing program executing program BUG: memory leak unreferenced object 0xffff88812421fe40 (size 64): comm "syz-executor330", pid 7117, jiffies 4294949245 (age 13.030s) hex dump (first 32 bytes): 01 00 00 00 20 69 6f 63 00 00 00 00 64 65 76 2f .... ioc....dev/ 50 fe 21 24 81 88 ff ff 50 fe 21 24 81 88 ff ff P.!$....P.!$.... backtrace: [<00000000ae0c4ae0>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] [<00000000ae0c4ae0>] slab_post_alloc_hook mm/slab.h:439 [inline] [<00000000ae0c4ae0>] slab_alloc mm/slab.c:3326 [inline] [<00000000ae0c4ae0>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 [<0000000079ebab38>] kmalloc include/linux/slab.h:547 [inline] [<0000000079ebab38>] vhost_net_ubuf_alloc drivers/vhost/net.c:241 [inline] [<0000000079ebab38>] vhost_net_set_backend drivers/vhost/net.c:1534 [inline] [<0000000079ebab38>] vhost_net_ioctl+0xb43/0xc10 drivers/vhost/net.c:1716 [<000000009f6204a2>] vfs_ioctl fs/ioctl.c:46 [inline] [<000000009f6204a2>] file_ioctl fs/ioctl.c:509 [inline] [<000000009f6204a2>] do_vfs_ioctl+0x62a/0x810 fs/ioctl.c:696 [<00000000b45866de>] ksys_ioctl+0x86/0xb0 fs/ioctl.c:713 [<00000000dfb41eb8>] __do_sys_ioctl fs/ioctl.c:720 [inline] [<00000000dfb41eb8>] __se_sys_ioctl fs/ioctl.c:718 [inline] [<00000000dfb41eb8>] __x64_sys_ioctl+0x1e/0x30 fs/ioctl.c:718 [<0000000049c1f547>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 [<0000000029cc8ca7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 BUG: memory leak unreferenced object 0xffff88812421fa80 (size 64): comm "syz-executor330", pid 7130, jiffies 4294949755 (age 7.930s) hex dump (first 32 bytes): 01 00 00 00 01 00 00 00 00 00 00 00 2f 76 69 72 ............/vir 90 fa 21 24 81 88 ff ff 90 fa 21 24 81 88 ff ff ..!$......!$.... backtrace: [<00000000ae0c4ae0>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] [<00000000ae0c4ae0>] slab_post_alloc_hook mm/slab.h:439 [inline] [<00000000ae0c4ae0>] slab_alloc mm/slab.c:3326 [inline] [<00000000ae0c4ae0>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 [<0000000079ebab38>] kmalloc include/linux/slab.h:547 [inline] [<0000000079ebab38>] vhost_net_ubuf_alloc drivers/vhost/net.c:241 [inline] [<0000000079ebab38>] vhost_net_set_backend drivers/vhost/net.c:1534 [inline] [<0000000079ebab38>] vhost_net_ioctl+0xb43/0xc10 drivers/vhost/net.c:1716 [<000000009f6204a2>] vfs_ioctl fs/ioctl.c:46 [inline] [<000000009f6204a2>] file_ioctl fs/ioctl.c:509 [inline] [<000000009f6204a2>] do_vfs_ioctl+0x62a/0x810 fs/ioctl.c:696 [<00000000b45866de>] ksys_ioctl+0x86/0xb0 fs/ioctl.c:713 [<00000000dfb41eb8>] __do_sys_ioctl fs/ioctl.c:720 [inline] [<00000000dfb41eb8>] __se_sys_ioctl fs/ioctl.c:718 [inline] [<00000000dfb41eb8>] __x64_sys_ioctl+0x1e/0x30 fs/ioctl.c:718 [<0000000049c1f547>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 [<0000000029cc8ca7>] 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 at googlegroups.com. 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