diff options
| author | Masatake YAMATO <yamato@redhat.com> | 2012-06-18 11:31:31 +0400 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2012-06-28 18:35:47 +0400 |
| commit | 44b8db13860a449b5d85afdc65da654ce56da678 (patch) | |
| tree | 1487b0bb967086607e50ce51a98eb1613b375b03 /fs/gfs2 | |
| parent | 666d1d8ad201803862514317c17695925e61316b (diff) | |
| download | linux-44b8db13860a449b5d85afdc65da654ce56da678.tar.xz | |
GFS2: Fixing double brelse'ing bh allocated in gfs2_meta_read when EIO occurs
This patch fixes buffer_head double free in following code path:
gfs2_block_map
=> gfs2_meta_inode_buffer
=> gfs2_meta_indirect_buffer
=> gfs2_meta_read
=> release_metapath
gfs2_block_map calls gfs2_meta_inode_buffer with &mp.mp_bh[0]
as an argument. mp.mp_bh are filled with zero at the beginning
of gfs2_block_map.
If gfs2_meta_inode_buffer returns non-zero value, gfs2_block_map
calls release_metapath to free buffers chained to mp.mp_bh.
release_metapath checks each slot of mp.mp_bh[i] and
free(with brelse) unless the slot is filled with NULL.
&mp.mp_bh[0] passed to gfs2_meta_inode_buffer is filled at
gfs2_meta_read. gfs2_meta_read is filled a buffer allocated with
gfs2_getbuf even if EIO occurs. When EIO occurs, the allocated buffer
is brelse'ed though the pointer(wrong poiner) points the brelse'ed is
passed back to caller via an argument bhp.
gfs2_meta_indirect_buffer, the caller also pass the wrong pointer
to its caller with EIO. Finally gfs2_block_map gets both EIO and
&mp.mp_bh[0] filled with the wrong pointer. release_metapath
calls brelse again on the wrong pointer.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2')
| -rw-r--r-- | fs/gfs2/meta_io.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c index 6c1e5d1c404a..3a56c8d94de0 100644 --- a/fs/gfs2/meta_io.c +++ b/fs/gfs2/meta_io.c @@ -213,8 +213,10 @@ int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags, struct gfs2_sbd *sdp = gl->gl_sbd; struct buffer_head *bh; - if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) + if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { + *bhp = NULL; return -EIO; + } *bhp = bh = gfs2_getbuf(gl, blkno, CREATE); @@ -235,6 +237,7 @@ int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags, if (tr && tr->tr_touched) gfs2_io_error_bh(sdp, bh); brelse(bh); + *bhp = NULL; return -EIO; } |