diff options
| author | Yufen Yu <yuyufen@huawei.com> | 2018-02-06 17:39:15 +0800 |
|---|---|---|
| committer | Shaohua Li <sh.li@alibaba-inc.com> | 2018-02-19 09:40:36 -0800 |
| commit | 01a69cab01c184d3786af09e9339311123d63d22 (patch) | |
| tree | 6741de4025476a9d0db6e1811d7b5e838fa65da8 /drivers/md/raid10.c | |
| parent | 39772f0a7be3b3dc26c74ea13fe7847fd1522c8b (diff) | |
| download | linux-01a69cab01c184d3786af09e9339311123d63d22.tar.gz | |
md raid10: fix NULL deference in handle_write_completed()
In the case of 'recover', an r10bio with R10BIO_WriteError &
R10BIO_IsRecover will be progressed by handle_write_completed().
This function traverses all r10bio->devs[copies].
If devs[m].repl_bio != NULL, it thinks conf->mirrors[dev].replacement
is also not NULL. However, this is not always true.
When there is an rdev of raid10 has replacement, then each r10bio
->devs[m].repl_bio != NULL in conf->r10buf_pool. However, in 'recover',
even if corresponded replacement is NULL, it doesn't clear r10bio
->devs[m].repl_bio, resulting in replacement NULL deference.
This bug was introduced when replacement support for raid10 was
added in Linux 3.3.
As NeilBrown suggested:
Elsewhere the determination of "is this device part of the
resync/recovery" is made by resting bio->bi_end_io.
If this is end_sync_write, then we tried to write here.
If it is NULL, then we didn't try to write.
Fixes: 9ad1aefc8ae8 ("md/raid10: Handle replacement devices during resync.")
Cc: stable (V3.3+)
Suggested-by: NeilBrown <neilb@suse.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Shaohua Li <sh.li@alibaba-inc.com>
Diffstat (limited to 'drivers/md/raid10.c')
| -rw-r--r-- | drivers/md/raid10.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 8d7ddc947d9d..9e9441fde8b3 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -2655,7 +2655,8 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio) for (m = 0; m < conf->copies; m++) { int dev = r10_bio->devs[m].devnum; rdev = conf->mirrors[dev].rdev; - if (r10_bio->devs[m].bio == NULL) + if (r10_bio->devs[m].bio == NULL || + r10_bio->devs[m].bio->bi_end_io == NULL) continue; if (!r10_bio->devs[m].bio->bi_status) { rdev_clear_badblocks( @@ -2670,7 +2671,8 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio) md_error(conf->mddev, rdev); } rdev = conf->mirrors[dev].replacement; - if (r10_bio->devs[m].repl_bio == NULL) + if (r10_bio->devs[m].repl_bio == NULL || + r10_bio->devs[m].repl_bio->bi_end_io == NULL) continue; if (!r10_bio->devs[m].repl_bio->bi_status) { |