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| author | Mike Snitzer <snitzer@redhat.com> | 2018-03-29 23:31:32 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2018-03-29 23:31:32 -0400 |
| commit | da5dadb4f11660ca67580cd4a7420161266d6254 (patch) | |
| tree | 6dacbd021d8c2d9f494aab81ee8a095fc22664ea /drivers/md | |
| parent | e457edf0b21c873be827b7c2f6b8e1545485c415 (diff) | |
| download | linux-da5dadb4f11660ca67580cd4a7420161266d6254.tar.bz2 | |
dm: fix dropped return code from dm_get_bdev_for_ioctl
dm_get_bdev_for_ioctl()'s return of 0 or 1 must be the result from
prepare_ioctl (1 means the ioctl was issued to a partition, 0 means it
wasn't). Unfortunately commit 519049afea ("dm: use blkdev_get rather
than bdgrab when issuing pass-through ioctl") reused the variable 'r'
to store the return from blkdev_get() that follows prepare_ioctl()
-- whereby dropping prepare_ioctl()'s result on the floor.
This can lead to an ioctl or persistent reservation being issued to a
partition going unnoticed, which implies the extra permission check for
CAP_SYS_RAWIO is skipped.
Fix this by using a different variable to store blkdev_get()'s return.
Fixes: 519049afea ("dm: use blkdev_get rather than bdgrab when issuing pass-through ioctl")
Reported-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 45328d8b2859..353ea0ede091 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -466,7 +466,7 @@ static int dm_get_bdev_for_ioctl(struct mapped_device *md, { struct dm_target *tgt; struct dm_table *map; - int srcu_idx, r; + int srcu_idx, r, r2; retry: r = -ENOTTY; @@ -492,9 +492,11 @@ retry: goto out; bdgrab(*bdev); - r = blkdev_get(*bdev, *mode, _dm_claim_ptr); - if (r < 0) + r2 = blkdev_get(*bdev, *mode, _dm_claim_ptr); + if (r2 < 0) { + r = r2; goto out; + } dm_put_live_table(md, srcu_idx); return r; |