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| author | Eric Biggers <ebiggers@google.com> | 2023-01-21 12:32:00 -0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2023-01-27 12:33:59 -0500 |
| commit | ae92b8f549cfc02f2231b3639ddf8a1b50b379ad (patch) | |
| tree | bf8d82c8c3c9525f689075a0ec0567e53c151a90 | |
| parent | c49ed1fe5fae98fa6272fdb205f34cef4c63aeb3 (diff) | |
| download | e2fsprogs-ae92b8f549cfc02f2231b3639ddf8a1b50b379ad.tar.gz | |
lib/blkid: fix unaligned access to hfs_mdb
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 <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | lib/blkid/probe.c | 10 |
1 files 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); |