linux/fs/nilfs2
Ryusuke Konishi 7633355e5c nilfs2: fix general protection fault in nilfs_btree_insert()
If nilfs2 reads a corrupted disk image and tries to reads a b-tree node
block by calling __nilfs_btree_get_block() against an invalid virtual
block address, it returns -ENOENT because conversion of the virtual block
address to a disk block address fails.  However, this return value is the
same as the internal code that b-tree lookup routines return to indicate
that the block being searched does not exist, so functions that operate on
that b-tree may misbehave.

When nilfs_btree_insert() receives this spurious 'not found' code from
nilfs_btree_do_lookup(), it misunderstands that the 'not found' check was
successful and continues the insert operation using incomplete lookup path
data, causing the following crash:

 general protection fault, probably for non-canonical address
 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
 KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
 ...
 RIP: 0010:nilfs_btree_get_nonroot_node fs/nilfs2/btree.c:418 [inline]
 RIP: 0010:nilfs_btree_prepare_insert fs/nilfs2/btree.c:1077 [inline]
 RIP: 0010:nilfs_btree_insert+0x6d3/0x1c10 fs/nilfs2/btree.c:1238
 Code: bc 24 80 00 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89
 ff e8 4b 02 92 fe 4d 8b 3f 49 83 c7 28 4c 89 f8 48 c1 e8 03 <42> 80 3c
 28 00 74 08 4c 89 ff e8 2e 02 92 fe 4d 8b 3f 49 83 c7 02
 ...
 Call Trace:
 <TASK>
  nilfs_bmap_do_insert fs/nilfs2/bmap.c:121 [inline]
  nilfs_bmap_insert+0x20d/0x360 fs/nilfs2/bmap.c:147
  nilfs_get_block+0x414/0x8d0 fs/nilfs2/inode.c:101
  __block_write_begin_int+0x54c/0x1a80 fs/buffer.c:1991
  __block_write_begin fs/buffer.c:2041 [inline]
  block_write_begin+0x93/0x1e0 fs/buffer.c:2102
  nilfs_write_begin+0x9c/0x110 fs/nilfs2/inode.c:261
  generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772
  __generic_file_write_iter+0x176/0x400 mm/filemap.c:3900
  generic_file_write_iter+0xab/0x310 mm/filemap.c:3932
  call_write_iter include/linux/fs.h:2186 [inline]
  new_sync_write fs/read_write.c:491 [inline]
  vfs_write+0x7dc/0xc50 fs/read_write.c:584
  ksys_write+0x177/0x2a0 fs/read_write.c:637
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
 ...
 </TASK>

This patch fixes the root cause of this problem by replacing the error
code that __nilfs_btree_get_block() returns on block address conversion
failure from -ENOENT to another internal code -EINVAL which means that the
b-tree metadata is corrupted.

By returning -EINVAL, it propagates without glitches, and for all relevant
b-tree operations, functions in the upper bmap layer output an error
message indicating corrupted b-tree metadata via
nilfs_bmap_convert_error(), and code -EIO will be eventually returned as
it should be.

Link: https://lkml.kernel.org/r/000000000000bd89e205f0e38355@google.com
Link: https://lkml.kernel.org/r/20230105055356.8811-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+ede796cecd5296353515@syzkaller.appspotmail.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-11 16:14:21 -08:00
..
alloc.c nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
alloc.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
bmap.c nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
bmap.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
btnode.c fs/nilfs2: Use the enum req_op and blk_opf_t types 2022-07-14 12:14:33 -06:00
btnode.h fs/nilfs2: Use the enum req_op and blk_opf_t types 2022-07-14 12:14:33 -06:00
btree.c nilfs2: fix general protection fault in nilfs_btree_insert() 2023-01-11 16:14:21 -08:00
btree.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
cpfile.c nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
cpfile.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
dat.c nilfs2: fix NULL pointer dereference in nilfs_palloc_commit_free_entry() 2022-11-30 14:49:40 -08:00
dat.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
dir.c nilfs2: Remove check for PageError 2022-06-29 08:51:07 -04:00
direct.c nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
direct.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
export.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
file.c nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
gcinode.c fs/nilfs2: Use the enum req_op and blk_opf_t types 2022-07-14 12:14:33 -06:00
ifile.c nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
ifile.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
inode.c nilfs2: fix NULL pointer dereference at nilfs_bmap_lookup_at_level() 2022-10-11 19:05:45 -07:00
ioctl.c block: add a bdev_discard_granularity helper 2022-04-17 19:49:59 -06:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mdt.c fs/nilfs2: Use the enum req_op and blk_opf_t types 2022-07-14 12:14:33 -06:00
mdt.h nilfs2: fix lockdep warnings during disk space reclamation 2022-04-01 11:46:09 -07:00
namei.c nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
nilfs.h nilfs2: fix incorrect masking of permission flags for symlinks 2022-07-03 15:42:33 -07:00
page.c nilfs2: convert nilfs_find_uncommited_extent() to use filemap_get_folios_contig() 2022-09-11 20:26:03 -07:00
page.h nilfs2: get rid of nilfs_mapping_init() 2022-04-01 11:46:09 -07:00
recovery.c fs: Remove aop flags parameter from block_write_begin() 2022-05-08 14:28:19 -04:00
segbuf.c Merge branch 'akpm' (patches from Andrew) 2022-03-22 16:11:53 -07:00
segbuf.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
segment.c treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
segment.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
sufile.c nilfs2: fix nilfs_sufile_mark_dirty() not set segment usage as dirty 2022-11-22 18:50:45 -08:00
sufile.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
super.c nilfs2: fix use-after-free bug of ns_writer on remount 2022-11-08 15:57:24 -08:00
sysfs.c nilfs2: use default_groups in kobj_type 2021-12-29 10:53:48 +01:00
sysfs.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00
the_nilfs.c Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -08:00
the_nilfs.h nilfs2: remove filenames from file comments 2021-11-09 10:02:52 -08:00