Hello,
syzbot found the following crash on:
HEAD commit: 9e50b94b Add linux-next specific files for 20200703 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=121cf755100000 kernel config: https://syzkaller.appspot.com/x/.config?x=f99cc0faa1476ed6 dashboard link: https://syzkaller.appspot.com/bug?extid=4342719956b367864c91 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1467c5e3100000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=153f2283100000
IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+4342719956b367864c91@syzkaller.appspotmail.com
RBP: 00000000000103d6 R08: 0000000000000001 R09: 00000000004002c8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402170 R13: 0000000000402200 R14: 0000000000000000 R15: 0000000000000000 general protection fault, probably for non-canonical address 0xdffffc0000000017: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000b8-0x00000000000000bf] CPU: 1 PID: 6798 Comm: syz-executor223 Not tainted 5.8.0-rc3-next-20200703-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dma_buf_release+0x51/0x3f0 drivers/dma-buf/dma-buf.c:63 Code: 03 80 3c 02 00 0f 85 30 03 00 00 48 8b ad e8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bd b8 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e e3 02 00 00 8b 9d b8 00 00 00 RSP: 0018:ffffc90001b87aa0 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffffffff847e30a0 RCX: ffffffff81c58a83 RDX: 0000000000000017 RSI: ffffffff847e30b0 RDI: 00000000000000b8 RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88808a53c80b R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808b7dc550 R13: ffff88808b7dc4d8 R14: ffff88808b7dc520 R15: 0000000000000000 FS: 0000000001f09880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006cc090 CR3: 00000000a87d2000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __dentry_kill+0x42b/0x640 fs/dcache.c:584 dentry_kill fs/dcache.c:705 [inline] dput+0x725/0xbc0 fs/dcache.c:878 path_put+0x2d/0x60 fs/namei.c:496 alloc_file_pseudo+0x20d/0x250 fs/file_table.c:236 dma_buf_getfile drivers/dma-buf/dma-buf.c:439 [inline] dma_buf_export+0x5d8/0xae0 drivers/dma-buf/dma-buf.c:555 udmabuf_create+0xb9d/0xe30 drivers/dma-buf/udmabuf.c:228 udmabuf_ioctl_create_list drivers/dma-buf/udmabuf.c:284 [inline] udmabuf_ioctl+0x265/0x2c0 drivers/dma-buf/udmabuf.c:299 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:753 __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl fs/ioctl.c:760 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:367 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x441229 Code: Bad RIP value. RSP: 002b:00007ffe24394848 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441229 RDX: 0000000020000000 RSI: 0000000040087543 RDI: 0000000000000004 RBP: 00000000000103d6 R08: 0000000000000001 R09: 00000000004002c8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402170 R13: 0000000000402200 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace 1a68562902844a66 ]--- RIP: 0010:dma_buf_release+0x51/0x3f0 drivers/dma-buf/dma-buf.c:63 Code: 03 80 3c 02 00 0f 85 30 03 00 00 48 8b ad e8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bd b8 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e e3 02 00 00 8b 9d b8 00 00 00 RSP: 0018:ffffc90001b87aa0 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffffffff847e30a0 RCX: ffffffff81c58a83 RDX: 0000000000000017 RSI: ffffffff847e30b0 RDI: 00000000000000b8 RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88808a53c80b R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808b7dc550 R13: ffff88808b7dc4d8 R14: ffff88808b7dc520 R15: 0000000000000000 FS: 0000000001f09880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006cc090 CR3: 00000000a87d2000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
--- 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@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