syzbot


KASAN: slab-use-after-free Read in add_ra_bio_pages (3)

Status: upstream: reported on 2024/07/04 14:52
Subsystems: btrfs
[Documentation on labels]
Reported-by: syzbot+853d80cba98ce1157ae6@syzkaller.appspotmail.com
Fix commit: 8e7860543a94 btrfs: fix extent map use-after-free when adding pages to compressed bio
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci2-upstream-fs ci2-upstream-kcsan-gce], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-riscv64 ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-net-next-test-gce ci2-upstream-usb]
First crash: 26d, last: 26d
Discussions (3)
Title Replies (including bot) Last reply
[PATCH v2] btrfs: Fix slab-use-after-free Read in add_ra_bio_pages 3 (3) 2024/07/11 06:38
[PATCH] btrfs: Fix slab-use-after-free Read in add_ra_bio_pages 2 (2) 2024/07/11 03:56
[syzbot] [btrfs?] KASAN: slab-use-after-free Read in add_ra_bio_pages (3) 0 (1) 2024/07/04 14:52
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in add_ra_bio_pages (2) btrfs 1 221d 217d 0/27 auto-obsoleted due to no activity on 2024/03/09 20:05
upstream KASAN: slab-use-after-free Read in add_ra_bio_pages btrfs 1 446d 442d 0/27 auto-obsoleted due to no activity on 2023/07/28 17:29

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in add_ra_bio_pages.constprop.0.isra.0+0xf03/0xfb0 fs/btrfs/compression.c:529
Read of size 8 at addr ffff88805a317178 by task syz-executor.2/12977

CPU: 0 PID: 12977 Comm: syz-executor.2 Not tainted 6.10.0-rc4-syzkaller-00283-g563a50672d8a #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 add_ra_bio_pages.constprop.0.isra.0+0xf03/0xfb0 fs/btrfs/compression.c:529
 btrfs_submit_compressed_read+0x5fb/0x930 fs/btrfs/compression.c:617
 submit_one_bio+0x15c/0x1c0 fs/btrfs/extent_io.c:118
 btrfs_readahead+0x132b/0x15c0 fs/btrfs/extent_io.c:2318
 read_pages+0x1a8/0xd80 mm/readahead.c:160
 page_cache_ra_unbounded+0x2d8/0x5a0 mm/readahead.c:273
 do_page_cache_ra mm/readahead.c:303 [inline]
 page_cache_ra_order+0x6e5/0xae0 mm/readahead.c:547
 ondemand_readahead+0x520/0x1140 mm/readahead.c:669
 page_cache_sync_ra+0x174/0x1d0 mm/readahead.c:696
 page_cache_sync_readahead include/linux/pagemap.h:1306 [inline]
 filemap_get_pages+0xc01/0x1830 mm/filemap.c:2529
 filemap_read+0x3af/0xd10 mm/filemap.c:2625
 btrfs_file_read_iter+0x1dc/0x840 fs/btrfs/file.c:4025
 copy_splice_read+0x615/0xb80 fs/splice.c:365
 do_splice_read fs/splice.c:984 [inline]
 do_splice_read+0x2cf/0x380 fs/splice.c:959
 splice_direct_to_actor+0x2a4/0xa40 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x17e/0x250 fs/splice.c:1233
 do_sendfile+0xb1e/0xe50 fs/read_write.c:1295
 __do_compat_sys_sendfile fs/read_write.c:1383 [inline]
 __se_compat_sys_sendfile fs/read_write.c:1366 [inline]
 __ia32_compat_sys_sendfile+0x1e7/0x230 fs/read_write.c:1366
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf72b9579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f5e8a5ac EFLAGS: 00000292 ORIG_RAX: 00000000000000bb
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000000004
RDX: 0000000000000000 RSI: 0000000000201005 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 12977:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3941 [inline]
 slab_alloc_node mm/slub.c:4001 [inline]
 kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4008
 alloc_extent_map+0x1c/0x100 fs/btrfs/extent_map.c:48
 btrfs_get_extent+0x223/0x1aa0 fs/btrfs/inode.c:6826
 btrfs_dio_iomap_begin+0x6e9/0x1e40 fs/btrfs/inode.c:7617
 iomap_iter+0x61f/0x1080 fs/iomap/iter.c:91
 __iomap_dio_rw+0x6ba/0x1c70 fs/iomap/direct-io.c:659
 iomap_dio_rw+0x40/0xa0 fs/iomap/direct-io.c:749
 btrfs_dio_read+0xb1/0xf0 fs/btrfs/inode.c:7881
 btrfs_direct_read fs/btrfs/file.c:3980 [inline]
 btrfs_file_read_iter+0x5c4/0x840 fs/btrfs/file.c:4019
 copy_splice_read+0x615/0xb80 fs/splice.c:365
 do_splice_read fs/splice.c:984 [inline]
 do_splice_read+0x2cf/0x380 fs/splice.c:959
 splice_direct_to_actor+0x2a4/0xa40 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x17e/0x250 fs/splice.c:1233
 do_sendfile+0xb1e/0xe50 fs/read_write.c:1295
 __do_compat_sys_sendfile fs/read_write.c:1383 [inline]
 __se_compat_sys_sendfile fs/read_write.c:1366 [inline]
 __ia32_compat_sys_sendfile+0x1e7/0x230 fs/read_write.c:1366
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Freed by task 12977:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2196 [inline]
 slab_free mm/slub.c:4437 [inline]
 kmem_cache_free+0x12f/0x3a0 mm/slub.c:4512
 free_extent_map fs/btrfs/extent_map.c:68 [inline]
 free_extent_map+0xeb/0x140 fs/btrfs/extent_map.c:61
 add_ra_bio_pages.constprop.0.isra.0+0x772/0xfb0 fs/btrfs/compression.c:517
 btrfs_submit_compressed_read+0x5fb/0x930 fs/btrfs/compression.c:617
 submit_one_bio+0x15c/0x1c0 fs/btrfs/extent_io.c:118
 btrfs_readahead+0x132b/0x15c0 fs/btrfs/extent_io.c:2318
 read_pages+0x1a8/0xd80 mm/readahead.c:160
 page_cache_ra_unbounded+0x2d8/0x5a0 mm/readahead.c:273
 do_page_cache_ra mm/readahead.c:303 [inline]
 page_cache_ra_order+0x6e5/0xae0 mm/readahead.c:547
 ondemand_readahead+0x520/0x1140 mm/readahead.c:669
 page_cache_sync_ra+0x174/0x1d0 mm/readahead.c:696
 page_cache_sync_readahead include/linux/pagemap.h:1306 [inline]
 filemap_get_pages+0xc01/0x1830 mm/filemap.c:2529
 filemap_read+0x3af/0xd10 mm/filemap.c:2625
 btrfs_file_read_iter+0x1dc/0x840 fs/btrfs/file.c:4025
 copy_splice_read+0x615/0xb80 fs/splice.c:365
 do_splice_read fs/splice.c:984 [inline]
 do_splice_read+0x2cf/0x380 fs/splice.c:959
 splice_direct_to_actor+0x2a4/0xa40 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x17e/0x250 fs/splice.c:1233
 do_sendfile+0xb1e/0xe50 fs/read_write.c:1295
 __do_compat_sys_sendfile fs/read_write.c:1383 [inline]
 __se_compat_sys_sendfile fs/read_write.c:1366 [inline]
 __ia32_compat_sys_sendfile+0x1e7/0x230 fs/read_write.c:1366
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff88805a317160
 which belongs to the cache btrfs_extent_map of size 112
The buggy address is located 24 bytes inside of
 freed 112-byte region [ffff88805a317160, ffff88805a3171d0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a317
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: 0xffffefff(slab)
raw: 04fff00000000000 ffff888025885900 ffffea0001570100 0000000000000006
raw: 0000000000000000 0000000080170017 00000001ffffefff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x152c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 40, tgid 40 (kworker/u32:2), ts 494044152115, free_ts 493554824903
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1468
 prep_new_page mm/page_alloc.c:1476 [inline]
 get_page_from_freelist+0x136a/0x2e50 mm/page_alloc.c:3420
 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4678
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x56/0x110 mm/slub.c:2265
 allocate_slab mm/slub.c:2428 [inline]
 new_slab+0x84/0x260 mm/slub.c:2481
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3667
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3757
 __slab_alloc_node mm/slub.c:3810 [inline]
 slab_alloc_node mm/slub.c:3989 [inline]
 kmem_cache_alloc_noprof+0x2ae/0x2f0 mm/slub.c:4008
 alloc_extent_map fs/btrfs/extent_map.c:48 [inline]
 btrfs_drop_extent_map_range+0xb7/0x13d0 fs/btrfs/extent_map.c:719
 btrfs_replace_extent_map_range+0xfb/0x1b0 fs/btrfs/extent_map.c:932
 create_io_em+0x22c/0x760 fs/btrfs/inode.c:7361
 cow_file_range+0x530/0xeb0 fs/btrfs/inode.c:1438
 run_delalloc_cow+0xa7/0x150 fs/btrfs/inode.c:1751
 submit_uncompressed_range.isra.0+0x124/0x350 fs/btrfs/inode.c:1128
 submit_one_async_extent fs/btrfs/inode.c:1179 [inline]
 submit_compressed_extents+0x732/0x13a0 fs/btrfs/inode.c:1641
 run_ordered_work fs/btrfs/async-thread.c:245 [inline]
 btrfs_work_helper+0x2d2/0xc90 fs/btrfs/async-thread.c:324
page last free pid 12763 tgid 12762 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1088 [inline]
 free_unref_page+0x64a/0xe40 mm/page_alloc.c:2583
 __folio_put+0x239/0x360 mm/swap.c:129
 folio_put include/linux/mm.h:1508 [inline]
 put_page include/linux/mm.h:1580 [inline]
 skb_page_unref include/linux/skbuff_ref.h:44 [inline]
 __skb_frag_unref include/linux/skbuff_ref.h:57 [inline]
 skb_release_data+0x5df/0x980 net/core/skbuff.c:1102
 skb_release_all net/core/skbuff.c:1173 [inline]
 __kfree_skb+0x4f/0x70 net/core/skbuff.c:1187
 tcp_wmem_free_skb include/net/tcp.h:306 [inline]
 tcp_write_queue_purge+0x188/0xd60 net/ipv4/tcp.c:3000
 tcp_v4_destroy_sock+0xfa/0x590 net/ipv4/tcp_ipv4.c:2524
 inet_csk_destroy_sock+0x1a3/0x450 net/ipv4/inet_connection_sock.c:1225
 __tcp_close+0xbfc/0xfe0 net/ipv4/tcp.c:2947
 tcp_close+0x28/0x130 net/ipv4/tcp.c:2959
 inet_release+0x13c/0x280 net/ipv4/af_inet.c:437
 __sock_release+0xb0/0x270 net/socket.c:659
 sock_close+0x1c/0x30 net/socket.c:1421
 __fput+0x408/0xbb0 fs/file_table.c:422
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 get_signal+0x1d3/0x2670 kernel/signal.c:2681
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310

Memory state around the buggy address:
 ffff88805a317000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff88805a317080: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb
>ffff88805a317100: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb
                                                                ^
 ffff88805a317180: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc
 ffff88805a317200: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/22 23:45 upstream 563a50672d8a c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: slab-use-after-free Read in add_ra_bio_pages
* Struck through repros no longer work on HEAD.