Re: BUG: sleeping function called from invalid context in crypto_drop_spawn

From: Matthew Wilcox
Date: Thu Jun 04 2020 - 21:22:06 EST


On Thu, Jun 04, 2020 at 05:40:31PM -0700, Eric Biggers wrote:
> +Cc linux-crypto. crypto_free_shash() is being called in atomic context;
> perhaps that should be allowed? kfree() can be called in atomic context.

Although vfree() cannot (which i personally hate ...)

> On Thu, Jun 04, 2020 at 05:33:19PM -0700, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: 39884604 mptcp: fix NULL ptr dereference in MP_JOIN error ..
> > git tree: net-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=1322a9ce100000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=55b0bb710b7fdf44
> > dashboard link: https://syzkaller.appspot.com/bug?extid=d769eed29cc42d75e2a3
> > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> >
> > Unfortunately, I don't have any reproducer for this crash yet.
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+d769eed29cc42d75e2a3@xxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1530
> > in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 15295, name: syz-executor.1
> > 6 locks held by syz-executor.1/15295:
> > #0: ffff88809740c430 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826
> > #1: ffff888214f62450 (sb_writers#3){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2908 [inline]
> > #1: ffff888214f62450 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x4cf/0x5d0 fs/read_write.c:558
> > #2: ffff88805241d488 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline]
> > #2: ffff88805241d488 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: ext4_buffered_write_iter+0xb3/0x450 fs/ext4/file.c:264
> > #3: ffff88805241d278 (&ei->i_data_sem){++++}-{3:3}, at: ext4_da_map_blocks fs/ext4/inode.c:1692 [inline]
> > #3: ffff88805241d278 (&ei->i_data_sem){++++}-{3:3}, at: ext4_da_get_block_prep+0xa0d/0x1120 fs/ext4/inode.c:1810
> > #4: ffff88805241d808 (&ei->i_es_lock){++++}-{2:2}, at: ext4_es_insert_delayed_block+0x12a/0x540 fs/ext4/extents_status.c:1982
> > #5: ffffc90000da8d60 ((&n->timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:193 [inline]
> > #5: ffffc90000da8d60 ((&n->timer)){+.-.}-{0:0}, at: call_timer_fn+0xdb/0x780 kernel/time/timer.c:1394
> > Preemption disabled at:
> > [<0000000000000000>] 0x0
> > CPU: 1 PID: 15295 Comm: syz-executor.1 Not tainted 5.7.0-rc6-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > Call Trace:
> > <IRQ>
> > __dump_stack lib/dump_stack.c:77 [inline]
> > dump_stack+0x188/0x20d lib/dump_stack.c:118
> > ___might_sleep.cold+0x1f4/0x23d kernel/sched/core.c:6800
> > down_write+0x6e/0x150 kernel/locking/rwsem.c:1530
> > crypto_drop_spawn crypto/algapi.c:707 [inline]
> > crypto_drop_spawn+0x4b/0x2b0 crypto/algapi.c:702
> > shash_free_singlespawn_instance+0x15/0x20 crypto/shash.c:593
> > crypto_free_instance crypto/algapi.c:68 [inline]
> > crypto_destroy_instance+0x7a/0xc0 crypto/algapi.c:76
> > crypto_alg_put crypto/internal.h:94 [inline]
> > crypto_alg_put crypto/internal.h:91 [inline]
> > crypto_mod_put crypto/api.c:45 [inline]
> > crypto_destroy_tfm+0x198/0x310 crypto/api.c:566
> > crypto_free_shash include/crypto/hash.h:722 [inline]
> > sctp_destruct_sock+0x37/0x50 net/sctp/socket.c:5231
> > __sk_destruct+0x4b/0x7c0 net/core/sock.c:1783
> > sk_destruct+0xc6/0x100 net/core/sock.c:1827
> > __sk_free+0xef/0x3d0 net/core/sock.c:1838
> > sock_wfree+0x129/0x240 net/core/sock.c:2064
> > skb_release_head_state+0xe2/0x250 net/core/skbuff.c:651
> > skb_release_all+0x11/0x60 net/core/skbuff.c:662
> > __kfree_skb net/core/skbuff.c:678 [inline]
> > kfree_skb net/core/skbuff.c:696 [inline]
> > kfree_skb+0xfa/0x410 net/core/skbuff.c:690
> > neigh_invalidate+0x25c/0x5c0 net/core/neighbour.c:993
> > neigh_timer_handler+0xdbb/0x1180 net/core/neighbour.c:1080
> > call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404
> > expire_timers kernel/time/timer.c:1449 [inline]
> > __run_timers kernel/time/timer.c:1773 [inline]
> > __run_timers kernel/time/timer.c:1740 [inline]
> > run_timer_softirq+0x623/0x1600 kernel/time/timer.c:1786
> > __do_softirq+0x26c/0x9f7 kernel/softirq.c:292
> > invoke_softirq kernel/softirq.c:373 [inline]
> > irq_exit+0x192/0x1d0 kernel/softirq.c:413
> > exiting_irq arch/x86/include/asm/apic.h:546 [inline]
> > smp_apic_timer_interrupt+0x19e/0x600 arch/x86/kernel/apic/apic.c:1140
> > apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
> > </IRQ>
> > RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:759 [inline]
> > RIP: 0010:lock_acquire+0x267/0x8f0 kernel/locking/lockdep.c:4937
> > Code: 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 c6 05 00 00 48 83 3d c5 2d 3b 08 00 0f 84 65 04 00 00 48 8b 3c 24 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 08 48 c7
> > RSP: 0018:ffffc90004fa74c8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
> > RAX: 1ffffffff132980c RBX: ffff8880868da440 RCX: 5e17927a8ce40e94
> > RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000282
> > RBP: 0000000000000000 R08: 0000000000000001 R09: fffffbfff1861546
> > R10: ffffffff8c30aa2f R11: fffffbfff1861545 R12: 0000000000000000
> > R13: ffff88805241d808 R14: 0000000000000000 R15: 0000000000000000
> > __raw_write_lock include/linux/rwlock_api_smp.h:210 [inline]
> > _raw_write_lock+0x2a/0x40 kernel/locking/spinlock.c:295
> > ext4_es_insert_delayed_block+0x12a/0x540 fs/ext4/extents_status.c:1982
> > ext4_insert_delayed_block fs/ext4/inode.c:1655 [inline]
> > ext4_da_map_blocks fs/ext4/inode.c:1746 [inline]
> > ext4_da_get_block_prep+0x6ea/0x1120 fs/ext4/inode.c:1810
> > ext4_block_write_begin+0x59a/0x1430 fs/ext4/inode.c:1053
> > ext4_da_write_begin+0x56e/0xbc0 fs/ext4/inode.c:2995
> > generic_perform_write+0x20a/0x4e0 mm/filemap.c:3302
> > ext4_buffered_write_iter+0x1f7/0x450 fs/ext4/file.c:270
> > ext4_file_write_iter+0x1ec/0x13f0 fs/ext4/file.c:642
> > call_write_iter include/linux/fs.h:1907 [inline]
> > new_sync_write+0x4a2/0x700 fs/read_write.c:484
> > __vfs_write+0xc9/0x100 fs/read_write.c:497
> > vfs_write+0x268/0x5d0 fs/read_write.c:559
> > ksys_write+0x12d/0x250 fs/read_write.c:612
> > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
> > entry_SYSCALL_64_after_hwframe+0x49/0xb3
> > RIP: 0033:0x45ca69
> > Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> > RSP: 002b:00007ff2b9d83c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> > RAX: ffffffffffffffda RBX: 000000000050c980 RCX: 000000000045ca69
> > RDX: 000000006db6e559 RSI: 0000000020000040 RDI: 0000000000000006
> > RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
> > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
> > R13: 0000000000000cec R14: 00000000004cf3d4 R15: 00007ff2b9d846d4
> >
> > =============================
> > [ BUG: Invalid wait context ]
> > 5.7.0-rc6-syzkaller #0 Tainted: G W
> > -----------------------------
> > syz-executor.1/15295 is trying to lock:
> > ffffffff89e64330 (crypto_alg_sem){++++}-{3:3}, at: crypto_drop_spawn crypto/algapi.c:707 [inline]
> > ffffffff89e64330 (crypto_alg_sem){++++}-{3:3}, at: crypto_drop_spawn+0x4b/0x2b0 crypto/algapi.c:702
> > other info that might help us debug this:
> > context-{2:2}
> > 6 locks held by syz-executor.1/15295:
> > #0: ffff88809740c430 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826
> > #1: ffff888214f62450 (sb_writers#3){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2908 [inline]
> > #1: ffff888214f62450 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x4cf/0x5d0 fs/read_write.c:558
> > #2: ffff88805241d488 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline]
> > #2: ffff88805241d488 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: ext4_buffered_write_iter+0xb3/0x450 fs/ext4/file.c:264
> > #3: ffff88805241d278 (&ei->i_data_sem){++++}-{3:3}, at: ext4_da_map_blocks fs/ext4/inode.c:1692 [inline]
> > #3: ffff88805241d278 (&ei->i_data_sem){++++}-{3:3}, at: ext4_da_get_block_prep+0xa0d/0x1120 fs/ext4/inode.c:1810
> > #4: ffff88805241d808 (&ei->i_es_lock){++++}-{2:2}, at: ext4_es_insert_delayed_block+0x12a/0x540 fs/ext4/extents_status.c:1982
> > #5: ffffc90000da8d60 ((&n->timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:193 [inline]
> > #5: ffffc90000da8d60 ((&n->timer)){+.-.}-{0:0}, at: call_timer_fn+0xdb/0x780 kernel/time/timer.c:1394
> > stack backtrace:
> > CPU: 1 PID: 15295 Comm: syz-executor.1 Tainted: G W 5.7.0-rc6-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > Call Trace:
> > <IRQ>
> > __dump_stack lib/dump_stack.c:77 [inline]
> > dump_stack+0x188/0x20d lib/dump_stack.c:118
> > print_lock_invalid_wait_context kernel/locking/lockdep.c:4007 [inline]
> > check_wait_context kernel/locking/lockdep.c:4068 [inline]
> > __lock_acquire.cold+0x273/0x3f8 kernel/locking/lockdep.c:4305
> > lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934
> > down_write+0x8d/0x150 kernel/locking/rwsem.c:1531
> > crypto_drop_spawn crypto/algapi.c:707 [inline]
> > crypto_drop_spawn+0x4b/0x2b0 crypto/algapi.c:702
> > shash_free_singlespawn_instance+0x15/0x20 crypto/shash.c:593
> > crypto_free_instance crypto/algapi.c:68 [inline]
> > crypto_destroy_instance+0x7a/0xc0 crypto/algapi.c:76
> > crypto_alg_put crypto/internal.h:94 [inline]
> > crypto_alg_put crypto/internal.h:91 [inline]
> > crypto_mod_put crypto/api.c:45 [inline]
> > crypto_destroy_tfm+0x198/0x310 crypto/api.c:566
> > crypto_free_shash include/crypto/hash.h:722 [inline]
> > sctp_destruct_sock+0x37/0x50 net/sctp/socket.c:5231
> > __sk_destruct+0x4b/0x7c0 net/core/sock.c:1783
> > sk_destruct+0xc6/0x100 net/core/sock.c:1827
> > __sk_free+0xef/0x3d0 net/core/sock.c:1838
> > sock_wfree+0x129/0x240 net/core/sock.c:2064
> > skb_release_head_state+0xe2/0x250 net/core/skbuff.c:651
> > skb_release_all+0x11/0x60 net/core/skbuff.c:662
> > __kfree_skb net/core/skbuff.c:678 [inline]
> > kfree_skb net/core/skbuff.c:696 [inline]
> > kfree_skb+0xfa/0x410 net/core/skbuff.c:690
> > neigh_invalidate+0x25c/0x5c0 net/core/neighbour.c:993
> > neigh_timer_handler+0xdbb/0x1180 net/core/neighbour.c:1080
> > call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404
> > expire_timers kernel/time/timer.c:1449 [inline]
> > __run_timers kernel/time/timer.c:1773 [inline]
> > __run_timers kernel/time/timer.c:1740 [inline]
> > run_timer_softirq+0x623/0x1600 kernel/time/timer.c:1786
> > __do_softirq+0x26c/0x9f7 kernel/softirq.c:292
> > invoke_softirq kernel/softirq.c:373 [inline]
> > irq_exit+0x192/0x1d0 kernel/softirq.c:413
> > exiting_irq arch/x86/include/asm/apic.h:546 [inline]
> > smp_apic_timer_interrupt+0x19e/0x600 arch/x86/kernel/apic/apic.c:1140
> > apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
> > </IRQ>
> > RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:759 [inline]
> > RIP: 0010:lock_acquire+0x267/0x8f0 kernel/locking/lockdep.c:4937
> > Code: 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 c6 05 00 00 48 83 3d c5 2d 3b 08 00 0f 84 65 04 00 00 48 8b 3c 24 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 08 48 c7
> > RSP: 0018:ffffc90004fa74c8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
> > RAX: 1ffffffff132980c RBX: ffff8880868da440 RCX: 5e17927a8ce40e94
> > RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000282
> > RBP: 0000000000000000 R08: 0000000000000001 R09: fffffbfff1861546
> > R10: ffffffff8c30aa2f R11: fffffbfff1861545 R12: 0000000000000000
> > R13: ffff88805241d808 R14: 0000000000000000 R15: 0000000000000000
> > __raw_write_lock include/linux/rwlock_api_smp.h:210 [inline]
> > _raw_write_lock+0x2a/0x40 kernel/locking/spinlock.c:295
> > ext4_es_insert_delayed_block+0x12a/0x540 fs/ext4/extents_status.c:1982
> > ext4_insert_delayed_block fs/ext4/inode.c:1655 [inline]
> > ext4_da_map_blocks fs/ext4/inode.c:1746 [inline]
> > ext4_da_get_block_prep+0x6ea/0x1120 fs/ext4/inode.c:1810
> > ext4_block_write_begin+0x59a/0x1430 fs/ext4/inode.c:1053
> > ext4_da_write_begin+0x56e/0xbc0 fs/ext4/inode.c:2995
> > generic_perform_write+0x20a/0x4e0 mm/filemap.c:3302
> > ext4_buffered_write_iter+0x1f7/0x450 fs/ext4/file.c:270
> > ext4_file_write_iter+0x1ec/0x13f0 fs/ext4/file.c:642
> > call_write_iter include/linux/fs.h:1907 [inline]
> > new_sync_write+0x4a2/0x700 fs/read_write.c:484
> > __vfs_write+0xc9/0x100 fs/read_write.c:497
> > vfs_write+0x268/0x5d0 fs/read_write.c:559
> > ksys_write+0x12d/0x250 fs/read_write.c:612
> > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
> > entry_SYSCALL_64_after_hwframe+0x49/0xb3
> > RIP: 0033:0x45ca69
> > Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> > RSP: 002b:00007ff2b9d83c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> > RAX: ffffffffffffffda RBX: 000000000050c980 RCX: 000000000045ca69
> > RDX: 000000006db6e559 RSI: 0000000020000040 RDI: 0000000000000006
> > RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
> > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
> > R13: 0000000000000cec R14: 00000000004cf3d4 R15: 00007ff2b9d846d4
> >
> >
> > ---
> > 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@xxxxxxxxxxxxxxxxx
> >
> > syzbot will keep track of this bug report. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >
> > --
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