From: Eric Biggers <[email protected]>
With -Wall, gcc warns:
./probe.c:1209:42: error: taking address of packed member of
'struct hfs_mdb' may result in an unaligned pointer value
This seems to be a real unaligned memory access bug, as the offset of
the 64-bit value from the start of the buffer is 116, which is not a
multiple of 8. Fix it by using memcpy().
Do the same for hfsplus to fix the same warning, though in that case the
offset is a multiple of 8 so it was defined behavior.
Signed-off-by: Eric Biggers <[email protected]>
---
lib/blkid/probe.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/lib/blkid/probe.c b/lib/blkid/probe.c
index b8b6558e3..6a3bb2478 100644
--- a/lib/blkid/probe.c
+++ b/lib/blkid/probe.c
@@ -1198,7 +1198,6 @@ static int probe_hfs(struct blkid_probe *probe __BLKID_ATTR((unused)),
unsigned char *buf)
{
struct hfs_mdb *hfs = (struct hfs_mdb *)buf;
- unsigned long long *uuid_ptr;
char uuid_str[17];
__u64 uuid;
@@ -1206,8 +1205,8 @@ static int probe_hfs(struct blkid_probe *probe __BLKID_ATTR((unused)),
(memcmp(hfs->embed_sig, "HX", 2) == 0))
return 1; /* Not hfs, but an embedded HFS+ */
- uuid_ptr = (unsigned long long *)hfs->finder_info.id;
- uuid = blkid_le64(*uuid_ptr);
+ memcpy(&uuid, hfs->finder_info.id, 8);
+ uuid = blkid_le64(uuid);
if (uuid) {
sprintf(uuid_str, "%016llX", uuid);
blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
@@ -1243,7 +1242,6 @@ static int probe_hfsplus(struct blkid_probe *probe,
unsigned int leaf_node_size;
unsigned int leaf_block;
unsigned int label_len;
- unsigned long long *uuid_ptr;
__u64 leaf_off, uuid;
char uuid_str[17], label[512];
int ext;
@@ -1274,8 +1272,8 @@ static int probe_hfsplus(struct blkid_probe *probe,
(memcmp(hfsplus->signature, "HX", 2) != 0))
return 1;
- uuid_ptr = (unsigned long long *)hfsplus->finder_info.id;
- uuid = blkid_le64(*uuid_ptr);
+ memcpy(&uuid, hfsplus->finder_info.id, 8);
+ uuid = blkid_le64(uuid);
if (uuid) {
sprintf(uuid_str, "%016llX", uuid);
blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
--
2.39.0