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| author | Bob Peterson <rpeterso@redhat.com> | 2015-10-01 19:47:31 +0300 |
|---|---|---|
| committer | Bob Peterson <rpeterso@redhat.com> | 2015-10-01 20:00:59 +0300 |
| commit | 491e94f790982bec5a1334dd3db2708de3724bdf (patch) | |
| tree | 710667725821e752d23d6bb1b829bbe6cee0b958 | |
| parent | 6de20eb0dee4c802d9d228d6c08d00386e172e52 (diff) | |
| download | linux-491e94f790982bec5a1334dd3db2708de3724bdf.tar.xz | |
gfs2: Add missing else in trans_add_meta/data
This patch fixes a timing window that causes a segfault.
The problem is that bd can remain NULL throughout the function
and then reference that NULL pointer if the bh->b_private starts
out NULL, then someone sets it to non-NULL inside the locking.
In that case, bd still needs to be set.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| -rw-r--r-- | fs/gfs2/trans.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c index b95d0d625f32..0c1bde395062 100644 --- a/fs/gfs2/trans.c +++ b/fs/gfs2/trans.c @@ -176,6 +176,8 @@ void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh) unlock_buffer(bh); if (bh->b_private == NULL) bd = gfs2_alloc_bufdata(gl, bh, &gfs2_databuf_lops); + else + bd = bh->b_private; lock_buffer(bh); gfs2_log_lock(sdp); } @@ -236,6 +238,8 @@ void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh) lock_page(bh->b_page); if (bh->b_private == NULL) bd = gfs2_alloc_bufdata(gl, bh, &gfs2_buf_lops); + else + bd = bh->b_private; unlock_page(bh->b_page); lock_buffer(bh); gfs2_log_lock(sdp); |