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| author | Andreas Gruenbacher <agruenba@redhat.com> | 2024-03-11 15:51:59 +0100 |
|---|---|---|
| committer | Andreas Gruenbacher <agruenba@redhat.com> | 2024-04-09 18:35:57 +0200 |
| commit | 35264909e9d1973ab9aaa2a1b07cda70f12bb828 (patch) | |
| tree | 0b9c4378d590d4ba11cf3efb42d3f75676047b82 /fs/gfs2 | |
| parent | gfs2: Don't forget to complete delayed withdraw (diff) | |
| download | linux-35264909e9d1973ab9aaa2a1b07cda70f12bb828.tar.xz linux-35264909e9d1973ab9aaa2a1b07cda70f12bb828.zip | |
gfs2: Fix NULL pointer dereference in gfs2_log_flush
In gfs2_jindex_free(), set sdp->sd_jdesc to NULL under the log flush
lock to provide exclusion against gfs2_log_flush().
In gfs2_log_flush(), check if sdp->sd_jdesc is non-NULL before
dereferencing it. Otherwise, we could run into a NULL pointer
dereference when outstanding glock work races with an unmount
(glock_work_func -> run_queue -> do_xmote -> inode_go_sync ->
gfs2_log_flush).
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Diffstat (limited to 'fs/gfs2')
| -rw-r--r-- | fs/gfs2/log.c | 3 | ||||
| -rw-r--r-- | fs/gfs2/super.c | 4 |
2 files changed, 6 insertions, 1 deletions
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index 8cddf955ebc0..a6dd68b458ce 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -1108,7 +1108,8 @@ repeat: lops_before_commit(sdp, tr); if (gfs2_withdrawing_or_withdrawn(sdp)) goto out_withdraw; - gfs2_log_submit_bio(&sdp->sd_jdesc->jd_log_bio, REQ_OP_WRITE); + if (sdp->sd_jdesc) + gfs2_log_submit_bio(&sdp->sd_jdesc->jd_log_bio, REQ_OP_WRITE); if (gfs2_withdrawing_or_withdrawn(sdp)) goto out_withdraw; diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c index e5f79466340d..9de789b78bc5 100644 --- a/fs/gfs2/super.c +++ b/fs/gfs2/super.c @@ -67,9 +67,13 @@ void gfs2_jindex_free(struct gfs2_sbd *sdp) sdp->sd_journals = 0; spin_unlock(&sdp->sd_jindex_spin); + down_write(&sdp->sd_log_flush_lock); sdp->sd_jdesc = NULL; + up_write(&sdp->sd_log_flush_lock); + while (!list_empty(&list)) { jd = list_first_entry(&list, struct gfs2_jdesc, jd_list); + BUG_ON(jd->jd_log_bio); gfs2_free_journal_extents(jd); list_del(&jd->jd_list); iput(jd->jd_inode); |