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| author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2010-09-05 01:13:24 +0200 |
|---|---|---|
| committer | Philipp Reisner <philipp.reisner@linbit.com> | 2010-10-14 18:38:34 +0200 |
| commit | 1d53f09e170e477de67babd7a10e277479260d51 (patch) | |
| tree | c795de9e5aeaf8324eeb25ea20c7b94f573bca83 /drivers/block | |
| parent | 435f07402b3165b90592073bc0f8c6f8fa160ff9 (diff) | |
| download | op-kernel-dev-1d53f09e170e477de67babd7a10e277479260d51.zip op-kernel-dev-1d53f09e170e477de67babd7a10e277479260d51.tar.gz | |
drbd: fix potential kernel BUG (NULL deref)
BUG trace would look like:
lc_find
drbd_rs_complete_io
got_OVResult
drbd_asender
Could be triggered by explicit, or IO-error policy based,
detach during online-verify.
We may only dereference mdev->resync, if we first get_ldev(), as the
disk may break any time, causing mdev->resync to disappear once all
ldev references have been returned.
Already in flight online-verify requests or replies may still come in,
which we then need to ignore.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/drbd/drbd_receiver.c | 15 | ||||
| -rw-r--r-- | drivers/block/drbd/drbd_worker.c | 10 |
2 files changed, 19 insertions, 6 deletions
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 2c3edf0..e4e4edd 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -4241,10 +4241,13 @@ static int got_IsInSync(struct drbd_conf *mdev, struct p_header80 *h) update_peer_seq(mdev, be32_to_cpu(p->seq_num)); - drbd_rs_complete_io(mdev, sector); - drbd_set_in_sync(mdev, sector, blksize); - /* rs_same_csums is supposed to count in units of BM_BLOCK_SIZE */ - mdev->rs_same_csum += (blksize >> BM_BLOCK_SHIFT); + if (get_ldev(mdev)) { + drbd_rs_complete_io(mdev, sector); + drbd_set_in_sync(mdev, sector, blksize); + /* rs_same_csums is supposed to count in units of BM_BLOCK_SIZE */ + mdev->rs_same_csum += (blksize >> BM_BLOCK_SHIFT); + put_ldev(mdev); + } dec_rs_pending(mdev); atomic_add(blksize >> 9, &mdev->rs_sect_in); @@ -4423,6 +4426,9 @@ static int got_OVResult(struct drbd_conf *mdev, struct p_header80 *h) else ov_oos_print(mdev); + if (!get_ldev(mdev)) + return TRUE; + drbd_rs_complete_io(mdev, sector); dec_rs_pending(mdev); @@ -4437,6 +4443,7 @@ static int got_OVResult(struct drbd_conf *mdev, struct p_header80 *h) drbd_resync_finished(mdev); } } + put_ldev(mdev); return TRUE; } diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 0174319..c72a5fc 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -1027,7 +1027,10 @@ int w_e_end_csum_rs_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel) return 1; } - drbd_rs_complete_io(mdev, e->sector); + if (get_ldev(mdev)) { + drbd_rs_complete_io(mdev, e->sector); + put_ldev(mdev); + } di = e->digest; @@ -1134,7 +1137,10 @@ int w_e_end_ov_reply(struct drbd_conf *mdev, struct drbd_work *w, int cancel) /* after "cancel", because after drbd_disconnect/drbd_rs_cancel_all * the resync lru has been cleaned up already */ - drbd_rs_complete_io(mdev, e->sector); + if (get_ldev(mdev)) { + drbd_rs_complete_io(mdev, e->sector); + put_ldev(mdev); + } di = e->digest; |
