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authorKarel Zak2019-07-31 16:18:27 +0200
committerKarel Zak2019-07-31 16:31:10 +0200
commitc4d6d1c54dcd0eff701236d396d88b1fc6251768 (patch)
treef69ae05887909c69fedb2fa847e5ef221e886374
parentMerge branch '2019wk29' of https://github.com/kerolasa/util-linux (diff)
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libblkid: fix file descriptor leak in blkid_verify()
The function blkid_verify() uses private device file descriptor and uses blkid_probe_set_device() to assign the descriptor to low-level probing code. Unfortunately, close() in this case is not enough as the prober can internally open whole-disk device too. The library API has been extended so blkid_probe_set_device() deallocates and close previously used prober for whole-disk. This new functionality is used in blkid_verify() now. Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1734545 Signed-off-by: Karel Zak <kzak@redhat.com>
-rw-r--r--libblkid/src/probe.c19
-rw-r--r--libblkid/src/verify.c4
2 files changed, 19 insertions, 4 deletions
diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index 1ace06a68..ae1fc06d6 100644
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -846,10 +846,15 @@ failed:
* @off: begin of probing area
* @size: size of probing area (zero means whole device/file)
*
- * Assigns the device to probe control struct, resets internal buffers and
- * resets the current probing.
+ * Assigns the device to probe control struct, resets internal buffers, resets
+ * the current probing, and close previously associated device (if open by
+ * libblkid).
*
- * Returns: -1 in case of failure, or 0 on success.
+ * If @fd is < 0 than only resets the prober and returns 1. Note that
+ * blkid_reset_probe() keeps the device associated with the prober, but
+ * blkid_probe_set_device() does complete reset.
+ *
+ * Returns: -1 in case of failure, 0 on success and 1 on reset.
*/
int blkid_probe_set_device(blkid_probe pr, int fd,
blkid_loff_t off, blkid_loff_t size)
@@ -864,6 +869,11 @@ int blkid_probe_set_device(blkid_probe pr, int fd,
if ((pr->flags & BLKID_FL_PRIVATE_FD) && pr->fd >= 0)
close(pr->fd);
+ if (pr->disk_probe) {
+ blkid_free_probe(pr->disk_probe);
+ pr->disk_probe = NULL;
+ }
+
pr->flags &= ~BLKID_FL_PRIVATE_FD;
pr->flags &= ~BLKID_FL_TINY_DEV;
pr->flags &= ~BLKID_FL_CDROM_DEV;
@@ -879,6 +889,9 @@ int blkid_probe_set_device(blkid_probe pr, int fd,
pr->wipe_size = 0;
pr->wipe_chain = NULL;
+ if (fd < 0)
+ return 1;
+
#if defined(POSIX_FADV_RANDOM) && defined(HAVE_POSIX_FADVISE)
/* Disable read-ahead */
posix_fadvise(fd, 0, 0, POSIX_FADV_RANDOM);
diff --git a/libblkid/src/verify.c b/libblkid/src/verify.c
index dbc10f254..a78c9f8f2 100644
--- a/libblkid/src/verify.c
+++ b/libblkid/src/verify.c
@@ -184,9 +184,11 @@ blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
dev->bid_name, (long long)st.st_rdev, dev->bid_type));
}
- blkid_reset_probe(cache->probe);
+ /* reset prober */
blkid_probe_reset_superblocks_filter(cache->probe);
+ blkid_probe_set_device(cache->probe, -1, 0, 0);
close(fd);
+
return dev;
}