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| author | Paul Mackerras <paulus@samba.org> | 2011-12-12 11:00:56 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2011-12-12 11:00:56 -0500 |
| commit | b4611abfa98af8351bf32e8b9ecc9d3384931c37 (patch) | |
| tree | a1ff17e10c37207e83bc602cf1fc8045d778c8a5 /fs/ext4/extents.c | |
| parent | b5a7e97039a80fae673ccc115ce595d5b88fb4ee (diff) | |
| download | op-kernel-dev-b4611abfa98af8351bf32e8b9ecc9d3384931c37.zip op-kernel-dev-b4611abfa98af8351bf32e8b9ecc9d3384931c37.tar.gz | |
ext4: Fix crash due to getting bogus eh_depth value on big-endian systems
Commit 1939dd84b3 ("ext4: cleanup ext4_ext_grow_indepth code") added a
reference to ext4_extent_header.eh_depth, but forget to pass the value
read through le16_to_cpu. The result is a crash on big-endian
machines, such as this crash on a POWER7 server:
attempt to access beyond end of device
sda8: rw=0, want=776392648163376, limit=168558560
Unable to handle kernel paging request for data at address 0x6b6b6b6b6b6b6bcb
Faulting instruction address: 0xc0000000001f5f38
cpu 0x14: Vector: 300 (Data Access) at [c000001bd1aaecf0]
pc: c0000000001f5f38: .__brelse+0x18/0x60
lr: c0000000002e07a4: .ext4_ext_drop_refs+0x44/0x80
sp: c000001bd1aaef70
msr: 9000000000009032
dar: 6b6b6b6b6b6b6bcb
dsisr: 40000000
current = 0xc000001bd15b8010
paca = 0xc00000000ffe4600
pid = 19911, comm = flush-8:0
enter ? for help
[c000001bd1aaeff0] c0000000002e07a4 .ext4_ext_drop_refs+0x44/0x80
[c000001bd1aaf090] c0000000002e0c58 .ext4_ext_find_extent+0x408/0x4c0
[c000001bd1aaf180] c0000000002e145c .ext4_ext_insert_extent+0x2bc/0x14c0
[c000001bd1aaf2c0] c0000000002e3fb8 .ext4_ext_map_blocks+0x628/0x1710
[c000001bd1aaf420] c0000000002b2974 .ext4_map_blocks+0x224/0x310
[c000001bd1aaf4d0] c0000000002b7f2c .mpage_da_map_and_submit+0xbc/0x490
[c000001bd1aaf5a0] c0000000002b8688 .write_cache_pages_da+0x2c8/0x430
[c000001bd1aaf720] c0000000002b8b28 .ext4_da_writepages+0x338/0x670
[c000001bd1aaf8d0] c000000000157280 .do_writepages+0x40/0x90
[c000001bd1aaf940] c0000000001ea830 .writeback_single_inode+0xe0/0x530
[c000001bd1aafa00] c0000000001eb680 .writeback_sb_inodes+0x210/0x300
[c000001bd1aafb20] c0000000001ebc84 .__writeback_inodes_wb+0xd4/0x140
[c000001bd1aafbe0] c0000000001ebfec .wb_writeback+0x2fc/0x3e0
[c000001bd1aafce0] c0000000001ed770 .wb_do_writeback+0x2f0/0x300
[c000001bd1aafdf0] c0000000001ed848 .bdi_writeback_thread+0xc8/0x340
[c000001bd1aafed0] c0000000000c5494 .kthread+0xb4/0xc0
[c000001bd1aaff90] c000000000021f48 .kernel_thread+0x54/0x70
This is due to getting ext_depth(inode) == 0x101 and therefore running
off the end of the path array in ext4_ext_drop_refs into following
unallocated structures.
This fixes it by adding the necessary le16_to_cpu.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 61fa9e1..61cdb97 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -1095,7 +1095,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), ext4_idx_pblock(EXT_FIRST_INDEX(neh))); - neh->eh_depth = cpu_to_le16(neh->eh_depth + 1); + neh->eh_depth = cpu_to_le16(le16_to_cpu(neh->eh_depth) + 1); ext4_mark_inode_dirty(handle, inode); out: brelse(bh); |
