syzbot

loop0: detected capacity change from 0 to 32768
bcachefs (loop0): mounting version 1.7: mi_btree_bitmap opts=compression=lz4,nojournal_transaction_names
bcachefs (loop0): recovering from clean shutdown, journal seq 7
Unable to handle kernel paging request at virtual address dfff800000000004
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
Mem abort info:
  ESR = 0x0000000096000005
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x05: level 1 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[dfff800000000004] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 6250 Comm: syz-executor983 Tainted: G        W          6.10.0-rc3-syzkaller-gac2193b4b460 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : crypto_skcipher_alg include/crypto/skcipher.h:375 [inline]
pc : crypto_skcipher_encrypt+0x48/0x124 crypto/skcipher.c:637
lr : crypto_skcipher_encrypt+0x24/0x124 crypto/skcipher.c:635
sp : ffff80009a2759d0
x29: ffff80009a2759d0 x28: 0000000000000000 x27: dfff800000000000
x26: ffff80009a275fe0 x25: ffff80009a275a80 x24: ffff80009a275a60
x23: ffff0000c8482a80 x22: 0000000000000020 x21: dfff800000000000
x20: 0000000000000008 x19: ffff80009a275a80 x18: ffff0000d67d9a30
x17: 2065657274622074 x16: ffff80008ae35f00 x15: 0000000000000002
x14: 1ffff0001344eb56 x13: 0000000000000000 x12: 0000000000000000
x11: ffff70001344eb58 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : 0000000000000004 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : 0000000000000000 x3 : 0000000000000010
x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000020
Call trace:
 crypto_skcipher_alg include/crypto/skcipher.h:375 [inline]
 crypto_skcipher_encrypt+0x48/0x124 crypto/skcipher.c:637
 do_encrypt_sg fs/bcachefs/checksum.c:108 [inline]
 do_encrypt+0x558/0x6a0 fs/bcachefs/checksum.c:150
 gen_poly_key fs/bcachefs/checksum.c:191 [inline]
 bch2_checksum+0x1c0/0x784 fs/bcachefs/checksum.c:227
 bch2_btree_node_read_done+0x119c/0x4ac8 fs/bcachefs/btree_io.c:1074
 btree_node_read_work+0x50c/0xe04 fs/bcachefs/btree_io.c:1345
 bch2_btree_node_read+0x1f50/0x280c fs/bcachefs/btree_io.c:1730
 __bch2_btree_root_read fs/bcachefs/btree_io.c:1769 [inline]
 bch2_btree_root_read+0x2a8/0x534 fs/bcachefs/btree_io.c:1793
 read_btree_roots+0x21c/0x730 fs/bcachefs/recovery.c:475
 bch2_fs_recovery+0x31c4/0x5488 fs/bcachefs/recovery.c:803
 bch2_fs_start+0x30c/0x53c fs/bcachefs/super.c:1031
 bch2_fs_open+0x8b4/0xb64 fs/bcachefs/super.c:2123
 bch2_mount+0x4fc/0xe18 fs/bcachefs/fs.c:1917
 legacy_get_tree+0xd4/0x16c fs/fs_context.c:662
 vfs_get_tree+0x90/0x288 fs/super.c:1780
 do_new_mount+0x278/0x900 fs/namespace.c:3352
 path_mount+0x590/0xe04 fs/namespace.c:3679
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount fs/namespace.c:3875 [inline]
 __arm64_sys_mount+0x45c/0x594 fs/namespace.c:3875
 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
Code: 977849b2 f9400294 91006280 d343fc08 (38756908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	977849b2 	bl	0xfffffffffde126c8
   4:	f9400294 	ldr	x20, [x20]
   8:	91006280 	add	x0, x20, #0x18
   c:	d343fc08 	lsr	x8, x0, #3
* 10:	38756908 	ldrb	w8, [x8, x21] <-- trapping instruction