93edb8db94
commit d68b29584c25dbacd01ed44a3e45abb35353f1de upstream.
Commit 39d42fa96ba1 ("dm crypt: add flags to optionally bypass kcryptd
workqueues") made it possible for some code paths in dm-crypt to be
executed in softirq context, when the underlying driver processes IO
requests in interrupt/softirq context.
In this case sometimes when allocating a new crypto request we may get
a stacktrace like below:
[ 210.103008][ C0] BUG: sleeping function called from invalid context at mm/mempool.c:381
[ 210.104746][ C0] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2602, name: fio
[ 210.106599][ C0] CPU: 0 PID: 2602 Comm: fio Tainted: G W 5.10.0+ #50
[ 210.108331][ C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
[ 210.110212][ C0] Call Trace:
[ 210.110921][ C0] <IRQ>
[ 210.111527][ C0] dump_stack+0x7d/0xa3
[ 210.112411][ C0] ___might_sleep.cold+0x122/0x151
[ 210.113527][ C0] mempool_alloc+0x16b/0x2f0
[ 210.114524][ C0] ? __queue_work+0x515/0xde0
[ 210.115553][ C0] ? mempool_resize+0x700/0x700
[ 210.116586][ C0] ? crypt_endio+0x91/0x180
[ 210.117479][ C0] ? blk_update_request+0x757/0x1150
[ 210.118513][ C0] ? blk_mq_end_request+0x4b/0x480
[ 210.119572][ C0] ? blk_done_softirq+0x21d/0x340
[ 210.120628][ C0] ? __do_softirq+0x190/0x611
[ 210.121626][ C0] crypt_convert+0x29f9/0x4c00
[ 210.122668][ C0] ? _raw_spin_lock_irqsave+0x87/0xe0
[ 210.123824][ C0] ? kasan_set_track+0x1c/0x30
[ 210.124858][ C0] ? crypt_iv_tcw_ctr+0x4a0/0x4a0
[ 210.125930][ C0] ? kmem_cache_free+0x104/0x470
[ 210.126973][ C0] ? crypt_endio+0x91/0x180
[ 210.127947][ C0] kcryptd_crypt_read_convert+0x30e/0x420
[ 210.129165][ C0] blk_update_request+0x757/0x1150
[ 210.130231][ C0] blk_mq_end_request+0x4b/0x480
[ 210.131294][ C0] blk_done_softirq+0x21d/0x340
[ 210.132332][ C0] ? _raw_spin_lock+0x81/0xd0
[ 210.133289][ C0] ? blk_mq_stop_hw_queue+0x30/0x30
[ 210.134399][ C0] ? _raw_read_lock_irq+0x40/0x40
[ 210.135458][ C0] __do_softirq+0x190/0x611
[ 210.136409][ C0] ? handle_edge_irq+0x221/0xb60
[ 210.137447][ C0] asm_call_irq_on_stack+0x12/0x20
[ 210.138507][ C0] </IRQ>
[ 210.139118][ C0] do_softirq_own_stack+0x37/0x40
[ 210.140191][ C0] irq_exit_rcu+0x110/0x1b0
[ 210.141151][ C0] common_interrupt+0x74/0x120
[ 210.142171][ C0] asm_common_interrupt+0x1e/0x40
Fix this by allocating crypto requests with GFP_ATOMIC mask in
interrupt context.
Fixes: 39d42fa96ba1 ("dm crypt: add flags to optionally bypass kcryptd workqueues")
Cc: stable@vger.kernel.org # v5.9+
Reported-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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