------------[ cut here ]------------
WARNING: CPU: 0 PID: 5352 at fs/bcachefs/btree_iter.c:3194 __bch2_trans_kmalloc+0x50f/0x9d0 fs/bcachefs/btree_iter.c:3194
Modules linked in:
CPU: 0 UID: 0 PID: 5352 Comm: kworker/0:5 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: bcachefs_write_ref bch2_do_discards_fast_work
RIP: 0010:__bch2_trans_kmalloc+0x50f/0x9d0 fs/bcachefs/btree_iter.c:3194
Code: 00 28 00 00 e8 d2 5b 35 00 48 c7 c0 75 f7 ff ff 48 83 c4 48 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 72 06 95 fd 90 <0f> 0b 90 e9 d3 fb ff ff e8 64 06 95 fd 90 0f 0b 90 e9 dc fd ff ff
RSP: 0018:ffffc9000d4a6a70 EFLAGS: 00010293
RAX: ffffffff842ab4be RBX: ffff888051d7c000 RCX: ffff8880002d0000
RDX: 0000000000000000 RSI: 0000000000020000 RDI: 0000000000010000
RBP: 0000000000020000 R08: ffffc9000d4a6e70 R09: 0000000000000001
R10: ffffc9000d4a6d80 R11: fffff52001a94d7d R12: dffffc0000000000
R13: ffff888051d7c030 R14: 1ffff1100a3af800 R15: 0000000000000011
FS:  0000000000000000(0000) GS:ffff88808d210000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005562f51cd168 CR3: 0000000042cf5000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 bch2_trans_kmalloc_nomemzero_ip fs/bcachefs/btree_iter.h:586 [inline]
 bch2_trans_kmalloc_nomemzero fs/bcachefs/btree_iter.h:621 [inline]
 bch2_alloc_sectors_start_trans+0x1d59/0x1e80 fs/bcachefs/alloc_foreground.c:1251
 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:320 [inline]
 bch2_btree_reserve_get+0x641/0x1810 fs/bcachefs/btree_update_interior.c:534
 bch2_btree_update_start+0x18ff/0x1de0 fs/bcachefs/btree_update_interior.c:1289
 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1921
 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:914
 __bch2_trans_commit+0x1bb5/0x8870 fs/bcachefs/btree_trans_commit.c:1104
 bch2_trans_commit fs/bcachefs/btree_update.h:241 [inline]
 bch2_discard_one_bucket+0xa32/0x11a0 fs/bcachefs/alloc_background.c:1913
 bch2_do_discards_fast_one fs/bcachefs/alloc_background.c:2007 [inline]
 bch2_do_discards_fast_work+0x522/0xb40 fs/bcachefs/alloc_background.c:2042
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>