On Tue, 05 Jul 2022 08:53:15 -0400 Mimi Zohar wrote: > > Thank you for the reproducer. This seems to be a similar false > positive as was discussed: > https://lore.kernel.org/linux-unionfs/000000000000c5b77105b4c3546e@xxxxxxxxxx/ > > thanks, > Hi Mimi Please pick up the patch attached if it makes sense to you. Hillf > > On Sat, 2022-07-02 at 10:27 -0700, syzbot wrote: > > syzbot has found a reproducer for the following issue on: > > > > HEAD commit: 089866061428 Merge tag 'libnvdimm-fixes-5.19-rc5' of git:/.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=11dd91f0080000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=75c9ff14e1db87c0 > > dashboard link: https://syzkaller.appspot.com/bug?extid=b42fe626038981fb7bfa > > compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=167bafc0080000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11aad3e0080000 > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+b42fe626038981fb7bfa@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ====================================================== > > WARNING: possible circular locking dependency detected > > 5.19.0-rc4-syzkaller-00187-g089866061428 #0 Not tainted > > ------------------------------------------------------ > > syz-executor450/3829 is trying to acquire lock: > > ffff88807e574460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393 > > > > but task is already holding lock: > > ffff888074de91a0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x7d2/0x1c10 security/integrity/ima/ima_main.c:260 > > > > which lock already depends on the new lock. > > > > > > the existing dependency chain (in reverse order) is: > > > > -> #1 (&iint->mutex){+.+.}-{3:3}: > > lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 > > __mutex_lock_common+0x1de/0x26c0 kernel/locking/mutex.c:603 > > __mutex_lock kernel/locking/mutex.c:747 [inline] > > mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 > > process_measurement+0x7d2/0x1c10 security/integrity/ima/ima_main.c:260 > > ima_file_check+0xe7/0x160 security/integrity/ima/ima_main.c:517 > > do_open fs/namei.c:3522 [inline] > > path_openat+0x2705/0x2ec0 fs/namei.c:3653 > > do_filp_open+0x277/0x4f0 fs/namei.c:3680 > > do_sys_openat2+0x13b/0x500 fs/open.c:1278 > > do_sys_open fs/open.c:1294 [inline] > > __do_sys_open fs/open.c:1302 [inline] > > __se_sys_open fs/open.c:1298 [inline] > > __x64_sys_open+0x221/0x270 fs/open.c:1298 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > > > -> #0 (sb_writers#4){.+.+}-{0:0}: > > check_prev_add kernel/locking/lockdep.c:3095 [inline] > > check_prevs_add kernel/locking/lockdep.c:3214 [inline] > > validate_chain+0x185c/0x65c0 kernel/locking/lockdep.c:3829 > > __lock_acquire+0x129a/0x1f80 kernel/locking/lockdep.c:5053 > > lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 > > percpu_down_read include/linux/percpu-rwsem.h:51 [inline] > > __sb_start_write include/linux/fs.h:1699 [inline] > > sb_start_write+0x4d/0x1a0 include/linux/fs.h:1774 > > mnt_want_write+0x3b/0x80 fs/namespace.c:393 > > ovl_maybe_copy_up+0x124/0x190 fs/overlayfs/copy_up.c:1078 > > ovl_open+0x106/0x2a0 fs/overlayfs/file.c:152 > > do_dentry_open+0x789/0x1040 fs/open.c:848 > > vfs_open fs/open.c:981 [inline] > > dentry_open+0xc1/0x120 fs/open.c:997 > > ima_calc_file_hash+0x157/0x1cb0 security/integrity/ima/ima_crypto.c:557 > > ima_collect_measurement+0x3de/0x850 security/integrity/ima/ima_api.c:292 > > process_measurement+0xf87/0x1c10 security/integrity/ima/ima_main.c:337 > > ima_file_check+0xe7/0x160 security/integrity/ima/ima_main.c:517 > > do_open fs/namei.c:3522 [inline] > > path_openat+0x2705/0x2ec0 fs/namei.c:3653 > > do_filp_open+0x277/0x4f0 fs/namei.c:3680 > > do_sys_openat2+0x13b/0x500 fs/open.c:1278 > > do_sys_open fs/open.c:1294 [inline] > > __do_sys_open fs/open.c:1302 [inline] > > __se_sys_open fs/open.c:1298 [inline] > > __x64_sys_open+0x221/0x270 fs/open.c:1298 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > > > other info that might help us debug this: > > > > Possible unsafe locking scenario: > > > > CPU0 CPU1 > > ---- ---- > > lock(&iint->mutex); > > lock(sb_writers#4); > > lock(&iint->mutex); > > lock(sb_writers#4); > > > > *** DEADLOCK *** > > > > 1 lock held by syz-executor450/3829: > > #0: ffff888074de91a0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x7d2/0x1c10 security/integrity/ima/ima_main.c:260 > > > > stack backtrace: > > CPU: 1 PID: 3829 Comm: syz-executor450 Not tainted 5.19.0-rc4-syzkaller-00187-g089866061428 #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 > > Call Trace: > > <TASK> > > __dump_stack lib/dump_stack.c:88 [inline] > > dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 > > check_noncircular+0x2f7/0x3b0 kernel/locking/lockdep.c:2175 > > check_prev_add kernel/locking/lockdep.c:3095 [inline] > > check_prevs_add kernel/locking/lockdep.c:3214 [inline] > > validate_chain+0x185c/0x65c0 kernel/locking/lockdep.c:3829 > > __lock_acquire+0x129a/0x1f80 kernel/locking/lockdep.c:5053 > > lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 > > percpu_down_read include/linux/percpu-rwsem.h:51 [inline] > > __sb_start_write include/linux/fs.h:1699 [inline] > > sb_start_write+0x4d/0x1a0 include/linux/fs.h:1774 > > mnt_want_write+0x3b/0x80 fs/namespace.c:393 > > ovl_maybe_copy_up+0x124/0x190 fs/overlayfs/copy_up.c:1078 > > ovl_open+0x106/0x2a0 fs/overlayfs/file.c:152 > > do_dentry_open+0x789/0x1040 fs/open.c:848 > > vfs_open fs/open.c:981 [inline] > > dentry_open+0xc1/0x120 fs/open.c:997 > > ima_calc_file_hash+0x157/0x1cb0 security/integrity/ima/ima_crypto.c:557 > > ima_collect_measurement+0x3de/0x850 security/integrity/ima/ima_api.c:292 > > process_measurement+0xf87/0x1c10 security/integrity/ima/ima_main.c:337 > > ima_file_check+0xe7/0x160 security/integrity/ima/ima_main.c:517 > > do_open fs/namei.c:3522 [inline] > > path_openat+0x2705/0x2ec0 fs/namei.c:3653 > > do_filp_open+0x277/0x4f0 fs/namei.c:3680 > > do_sys_openat2+0x13b/0x500 fs/open.c:1278 > > do_sys_open fs/open.c:1294 [inline] > > __do_sys_open fs/open.c:1302 [inline] > > __se_sys_open fs/open.c:1298 [inline] > > __x64_sys_open+0x221/0x270 fs/open.c:1298 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > RIP: 0033:0x7faf98402749 > > Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 31 16 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 > > RSP: 002b:00007faf9838e2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 > > RAX: ffffffffffffffda RBX: 00007faf98491270 RCX: 00007faf98402749 > > RDX: 0000000000000000 RSI: 000000000000000b RDI: 00000000200000c0 > > RBP: 00007faf98458504 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e > > R13: 3d7269647265776f R14: 0079616c7265766f R15: 00007faf98491278 > > </TASK> > > --->8--- From: Hillf Danton <hdanton@xxxxxxxx> Subject: [PATCH] integrity: lockdep annotate of iint->mutex This fixes a reported lockdep splat CPU0 CPU1 ---- ---- lock(&iint->mutex); lock(sb_writers#4); lock(&iint->mutex); lock(sb_writers#4); *** DEADLOCK *** using the method in 4eae06de482b annotating OVL_I(inode)->lock. Links: https://lore.kernel.org/linux-unionfs/CAOQ4uxjk4XYuwz5HCmN-Ge=Ld=tM1f7ZxVrd5U1AC2Wisc9MTA@xxxxxxxxxxxxxx/ Reported-and-tested-by: syzbot <syzbot+b42fe626038981fb7bfa@xxxxxxxxxxxxxxxxxxxxxxxxx> Cc: Mimi Zohar <zohar@xxxxxxxxxxxxx> Cc: Amir Goldstein <amir73il@xxxxxxxxx> Signed-off-by: Hillf Danton <hdanton@xxxxxxxx> --- --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -85,6 +85,17 @@ static void iint_free(struct integrity_i kmem_cache_free(iint_cache, iint); } +static void iint_annotate_mutex_key(struct integrity_iint_cache *iint, struct inode *inode) +{ +#ifdef CONFIG_LOCKDEP + static struct lock_class_key iint_mutex_key[FILESYSTEM_MAX_STACK_DEPTH]; + + int depth = inode->i_sb->s_stack_depth; + + lockdep_set_class(&iint->mutex, &iint_mutex_key[depth]); +#endif +} + /** * integrity_inode_get - find or allocate an iint associated with an inode * @inode: pointer to the inode @@ -114,6 +125,8 @@ struct integrity_iint_cache *integrity_i if (!iint) return NULL; + iint_annotate_mutex_key(iint, inode); + write_lock(&integrity_iint_lock); p = &integrity_iint_tree.rb_node; --
