syzbot

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BUG: KASAN: use-after-free in memcpy_dir crypto/scatterwalk.c:23 [inline]
BUG: KASAN: use-after-free in scatterwalk_copychunks+0x1cc/0x460 crypto/scatterwalk.c:38
Read of size 40 at addr ffff88804a560000 by task syz-executor387/5315

CPU: 0 UID: 0 PID: 5315 Comm: syz-executor387 Not tainted 6.12.0-rc4-syzkaller-00256-gc71f8fb4dc91 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 memcpy_dir crypto/scatterwalk.c:23 [inline]
 scatterwalk_copychunks+0x1cc/0x460 crypto/scatterwalk.c:38
 skcipher_next_slow+0x39d/0x480 crypto/skcipher.c:276
 skcipher_walk_next+0x634/0xba0 crypto/skcipher.c:361
 chacha_simd_stream_xor+0x67f/0xd10 arch/x86/crypto/chacha_glue.c:192
 do_encrypt_sg fs/bcachefs/checksum.c:108 [inline]
 do_encrypt+0x992/0xd70 fs/bcachefs/checksum.c:124
 bset_encrypt fs/bcachefs/btree_io.h:118 [inline]
 bch2_btree_node_read_done+0x17b4/0x5e90 fs/bcachefs/btree_io.c:1115
 btree_node_read_work+0x68b/0x1260 fs/bcachefs/btree_io.c:1327
 bch2_btree_node_read+0x2433/0x2a10
 __bch2_btree_root_read fs/bcachefs/btree_io.c:1753 [inline]
 bch2_btree_root_read+0x617/0x7a0 fs/bcachefs/btree_io.c:1775
 read_btree_roots+0x296/0x840 fs/bcachefs/recovery.c:524
 bch2_fs_recovery+0x2585/0x39c0 fs/bcachefs/recovery.c:854
 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1036
 bch2_fs_get_tree+0xd68/0x1710 fs/bcachefs/fs.c:2170
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f32087a906a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffd10e92cf8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd10e92d10 RCX: 00007f32087a906a
RDX: 000000002000f700 RSI: 000000002000f680 RDI: 00007ffd10e92d10
RBP: 0000000000000004 R08: 00007ffd10e92d50 R09: 0037373737373737
R10: 0000000000000012 R11: 0000000000000282 R12: 0000000000000012
R13: 00007ffd10e92d50 R14: 0000000000000003 R15: 0000000001000000
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4a560
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 04fff00000000000 ffffea0001299808 ffff88805ffd7028 0000000000000000
raw: 0000000000000000 0000000000000005 00000000f0000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 5, migratetype Reclaimable, gfp_mask 0x452cd0(GFP_KERNEL_ACCOUNT|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_RECLAIMABLE), pid 5315, tgid 5315 (syz-executor387), ts 69953894182, free_ts 70025968736
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 ___kmalloc_large_node+0x8b/0x1d0 mm/slub.c:4209
 __kmalloc_large_node_noprof+0x1a/0x80 mm/slub.c:4236
 __do_kmalloc_node mm/slub.c:4252 [inline]
 __kmalloc_node_noprof+0x2d2/0x440 mm/slub.c:4270
 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:658
 btree_node_data_alloc+0xdb/0x260 fs/bcachefs/btree_cache.c:125
 __bch2_btree_node_mem_alloc+0x1e1/0x390 fs/bcachefs/btree_cache.c:170
 bch2_fs_btree_cache_init+0x26f/0x630 fs/bcachefs/btree_cache.c:633
 bch2_fs_alloc fs/bcachefs/super.c:916 [inline]
 bch2_fs_open+0x2aa4/0x2f80 fs/bcachefs/super.c:2064
 bch2_fs_get_tree+0x738/0x1710 fs/bcachefs/fs.c:2157
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
page last free pid 5315 tgid 5315 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 __free_pages_ok+0xa9c/0xc80 mm/page_alloc.c:1250
 __folio_put+0x2c7/0x440 mm/swap.c:126
 folio_put include/linux/mm.h:1478 [inline]
 free_large_kmalloc+0x105/0x1c0 mm/slub.c:4698
 kfree+0x21c/0x440 mm/slub.c:4721
 btree_bounce_free fs/bcachefs/btree_io.c:112 [inline]
 bch2_btree_node_read_done+0x3c8a/0x5e90 fs/bcachefs/btree_io.c:1213
 btree_node_read_work+0x68b/0x1260 fs/bcachefs/btree_io.c:1327
 bch2_btree_node_read+0x2433/0x2a10
 __bch2_btree_root_read fs/bcachefs/btree_io.c:1753 [inline]
 bch2_btree_root_read+0x617/0x7a0 fs/bcachefs/btree_io.c:1775
 read_btree_roots+0x296/0x840 fs/bcachefs/recovery.c:524
 bch2_fs_recovery+0x2585/0x39c0 fs/bcachefs/recovery.c:854
 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1036
 bch2_fs_get_tree+0xd68/0x1710 fs/bcachefs/fs.c:2170
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83

Memory state around the buggy address:
 ffff88804a55ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88804a55ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804a560000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88804a560080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804a560100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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