bisecting cause commit starting from 0011572c883082a95e02d47f45fc4a42dc0e8634 building syzkaller on 442206d76b974cca2d83ec763d4cf5ee829eb7d6 testing commit 0011572c883082a95e02d47f45fc4a42dc0e8634 with gcc (GCC) 8.1.0 all runs: crashed: BUG: Dentry still in use [unmount of sysfs sysfs] testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 all runs: OK # git bisect start 0011572c883082a95e02d47f45fc4a42dc0e8634 v5.1 Bisecting: 7699 revisions left to test after this (roughly 13 steps) [f4d9a23d3dad0252f375901bf4ff6523a2c97241] sparc64: simplify reduce_memory() function testing commit f4d9a23d3dad0252f375901bf4ff6523a2c97241 with gcc (GCC) 8.1.0 all runs: OK # git bisect good f4d9a23d3dad0252f375901bf4ff6523a2c97241 Bisecting: 3813 revisions left to test after this (roughly 12 steps) [318222a35bfb0ae9b5ff3e359a583463e6cfcd94] Merge branch 'akpm' (patches from Andrew) testing commit 318222a35bfb0ae9b5ff3e359a583463e6cfcd94 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 318222a35bfb0ae9b5ff3e359a583463e6cfcd94 Bisecting: 1935 revisions left to test after this (roughly 11 steps) [4489da7183099f569a7d3dd819c975073c04bc72] Merge tag 'nds32-for-linus-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/greentime/linux testing commit 4489da7183099f569a7d3dd819c975073c04bc72 with gcc (GCC) 8.1.0 all runs: crashed: BUG: Dentry still in use [unmount of sysfs sysfs] # git bisect bad 4489da7183099f569a7d3dd819c975073c04bc72 Bisecting: 1041 revisions left to test after this (roughly 10 steps) [22c58fd70ca48a29505922b1563826593b08cc00] Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc testing commit 22c58fd70ca48a29505922b1563826593b08cc00 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 22c58fd70ca48a29505922b1563826593b08cc00 Bisecting: 520 revisions left to test after this (roughly 9 steps) [fbadd4d12234fe8468843c3e24d83019cdbbea77] Merge tag 'qcom-dts-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/agross/linux into arm/dt testing commit fbadd4d12234fe8468843c3e24d83019cdbbea77 with gcc (GCC) 8.1.0 all runs: OK # git bisect good fbadd4d12234fe8468843c3e24d83019cdbbea77 Bisecting: 256 revisions left to test after this (roughly 8 steps) [d396360acdf7e57edcd9e2d080343b0353d65d63] Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit d396360acdf7e57edcd9e2d080343b0353d65d63 with gcc (GCC) 8.1.0 all runs: OK # git bisect good d396360acdf7e57edcd9e2d080343b0353d65d63 Bisecting: 122 revisions left to test after this (roughly 7 steps) [227747fb9eab37aaeb360aeba795362c01889427] Merge tag 'afs-fixes-20190516' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs testing commit 227747fb9eab37aaeb360aeba795362c01889427 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 227747fb9eab37aaeb360aeba795362c01889427 Bisecting: 77 revisions left to test after this (roughly 6 steps) [815d469d8c9a3360ee0a8b7857dd95352a6c7bde] Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux testing commit 815d469d8c9a3360ee0a8b7857dd95352a6c7bde with gcc (GCC) 8.1.0 all runs: OK # git bisect good 815d469d8c9a3360ee0a8b7857dd95352a6c7bde Bisecting: 38 revisions left to test after this (roughly 5 steps) [32fd90c407680935f84fb3ffc60fb3e020257d38] nvme: change locking for the per-subsystem controller list testing commit 32fd90c407680935f84fb3ffc60fb3e020257d38 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 32fd90c407680935f84fb3ffc60fb3e020257d38 Bisecting: 23 revisions left to test after this (roughly 4 steps) [bf8a9a4755737f6630756f0d87bea9b38f0ed369] Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs testing commit bf8a9a4755737f6630756f0d87bea9b38f0ed369 with gcc (GCC) 8.1.0 all runs: crashed: BUG: Dentry still in use [unmount of sysfs sysfs] # git bisect bad bf8a9a4755737f6630756f0d87bea9b38f0ed369 Bisecting: 8 revisions left to test after this (roughly 3 steps) [fdb288a679cdf6a71f3c1ae6f348ba4dae742681] io_uring: use wait_event_interruptible for cq_wait conditional wait testing commit fdb288a679cdf6a71f3c1ae6f348ba4dae742681 with gcc (GCC) 8.1.0 all runs: OK # git bisect good fdb288a679cdf6a71f3c1ae6f348ba4dae742681 Bisecting: 4 revisions left to test after this (roughly 2 steps) [1718de78e6235c04ecb7f87a6875fdf90aafe382] Merge tag 'for-5.2/block-post-20190516' of git://git.kernel.dk/linux-block testing commit 1718de78e6235c04ecb7f87a6875fdf90aafe382 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 1718de78e6235c04ecb7f87a6875fdf90aafe382 Bisecting: 2 revisions left to test after this (roughly 1 step) [9c8ad7a2ff0bfe58f019ec0abc1fb965114dde7d] uapi, x86: Fix the syscall numbering of the mount API syscalls [ver #2] testing commit 9c8ad7a2ff0bfe58f019ec0abc1fb965114dde7d with gcc (GCC) 8.1.0 all runs: crashed: BUG: Dentry still in use [unmount of sysfs sysfs] # git bisect bad 9c8ad7a2ff0bfe58f019ec0abc1fb965114dde7d Bisecting: 0 revisions left to test after this (roughly 0 steps) [1cdc415f10831c18912943017d06b2be948c67b4] uapi, fsopen: use square brackets around "fscontext" [ver #2] testing commit 1cdc415f10831c18912943017d06b2be948c67b4 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 1cdc415f10831c18912943017d06b2be948c67b4 9c8ad7a2ff0bfe58f019ec0abc1fb965114dde7d is the first bad commit commit 9c8ad7a2ff0bfe58f019ec0abc1fb965114dde7d Author: David Howells Date: Thu May 16 12:52:27 2019 +0100 uapi, x86: Fix the syscall numbering of the mount API syscalls [ver #2] Fix the syscall numbering of the mount API syscalls so that the numbers match between i386 and x86_64 and that they're in the common numbering scheme space. Fixes: a07b20004793 ("vfs: syscall: Add open_tree(2) to reference or clone a mount") Fixes: 2db154b3ea8e ("vfs: syscall: Add move_mount(2) to move mounts around") Fixes: 24dcb3d90a1f ("vfs: syscall: Add fsopen() to prepare for superblock creation") Fixes: ecdab150fddb ("vfs: syscall: Add fsconfig() for configuring and managing a context") Fixes: 93766fbd2696 ("vfs: syscall: Add fsmount() to create a mount for a superblock") Fixes: cf3cba4a429b ("vfs: syscall: Add fspick() to select a superblock for reconfiguration") Reported-by: Arnd Bergmann Signed-off-by: David Howells Reviewed-by: Arnd Bergmann Signed-off-by: Al Viro :040000 040000 31ed689f1b143c8216f3f9356682cc73b47da320 0d339e04fa9a857fb19df4c06195073f8eb67173 M arch revisions tested: 16, total time: 4h0m33.162716411s (build: 1h28m40.063502746s, test: 2h27m16.811903822s) first bad commit: 9c8ad7a2ff0bfe58f019ec0abc1fb965114dde7d uapi, x86: Fix the syscall numbering of the mount API syscalls [ver #2] cc: ["arnd@arndb.de" "axboe@kernel.dk" "bp@alien8.de" "catalin.marinas@arm.com" "christian@brauner.io" "dhowells@redhat.com" "geert@linux-m68k.org" "hare@suse.com" "heiko.carstens@de.ibm.com" "hpa@zytor.com" "linux-kernel@vger.kernel.org" "luto@kernel.org" "mingo@redhat.com" "tglx@linutronix.de" "tycho@tycho.ws" "viro@zeniv.linux.org.uk" "x86@kernel.org"] crash: BUG: Dentry still in use [unmount of sysfs sysfs] BUG: Dentry 00000000fe188a97{i=1,n=/} still in use (2) [unmount of sysfs sysfs] WARNING: CPU: 1 PID: 7400 at fs/dcache.c:1528 umount_check.cold.51+0xd2/0x13f fs/dcache.c:1519 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 7400 Comm: syz-executor.2 Not tainted 5.1.0+ #1 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+0x113/0x167 lib/dump_stack.c:113 panic+0x212/0x40b kernel/panic.c:214 __warn.cold.8+0x1b/0x38 kernel/panic.c:566 report_bug+0x1a4/0x200 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:179 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:972 RIP: 0010:umount_check.cold.51+0xd2/0x13f fs/dcache.c:1528 Code: c1 ea 03 80 3c 02 00 75 79 49 81 c4 68 06 00 00 41 89 d8 48 89 f1 41 54 4d 8b 0e 4c 89 ea 48 c7 c7 20 b3 f4 86 e8 1b 6c ae ff <0f> 0b 58 e9 00 48 ff ff 48 89 75 d8 e8 6b a5 f2 ff 48 8b 75 d8 e9 RSP: 0018:ffff88808116fbe0 EFLAGS: 00010282 RAX: 0000000000000050 RBX: 0000000000000002 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff89b40c80 RBP: ffff88808116fc10 R08: ffffed1015d66011 R09: ffffed1015d66010 R10: ffffed1015d66010 R11: ffff8880aeb30087 R12: ffff88808e39e6e8 R13: 0000000000000001 R14: ffffffff88280bc0 R15: ffff8880a96b2b98 d_walk+0x19b/0x6b0 fs/dcache.c:1263 do_one_tree+0x1f/0x40 fs/dcache.c:1535 shrink_dcache_for_umount+0x56/0x120 fs/dcache.c:1551 generic_shutdown_super+0x61/0x330 fs/super.c:443 kill_anon_super+0x38/0x60 fs/super.c:1137 kernfs_kill_sb+0x145/0x1c3 fs/kernfs/mount.c:361 sysfs_kill_sb+0x1a/0x30 fs/sysfs/mount.c:87 deactivate_locked_super+0x77/0xd0 fs/super.c:331 deactivate_super+0x136/0x150 fs/super.c:362 cleanup_mnt+0xa3/0x140 fs/namespace.c:1120 __cleanup_mnt+0xd/0x10 fs/namespace.c:1127 task_work_run+0x108/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x1a9/0x200 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:276 [inline] do_syscall_64+0x445/0x520 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x412fb1 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fff38f9d6b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000412fb1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007fff38f9d790 R11: 0000000000000293 R12: 00000000007601e0 R13: 000000000000fb27 R14: 000000000000fb54 R15: 000000000075bf2c Kernel Offset: disabled Rebooting in 86400 seconds..