diff options
| author | Stian Skjelstad <stian.skjelstad@gmail.com> | 2021-08-22 11:33:32 +0200 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2021-08-23 13:35:19 +0200 |
| commit | 58bc6d1be2f3b0ceecb6027dfa17513ec6aa2abb (patch) | |
| tree | 35c805c134c52f71af8a014a90c7e626412e4c4c /fs/udf | |
| parent | 28ce50f8d96ec9035f60c9348294ea26b94db944 (diff) | |
| download | lwn-58bc6d1be2f3b0ceecb6027dfa17513ec6aa2abb.tar.gz lwn-58bc6d1be2f3b0ceecb6027dfa17513ec6aa2abb.zip | |
udf_get_extendedattr() had no boundary checks.
When parsing the ExtendedAttr data, malicous or corrupt attribute length
could cause kernel hangs and buffer overruns in some special cases.
Link: https://lore.kernel.org/r/20210822093332.25234-1-stian.skjelstad@gmail.com
Signed-off-by: Stian Skjelstad <stian.skjelstad@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/udf')
| -rw-r--r-- | fs/udf/misc.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/fs/udf/misc.c b/fs/udf/misc.c index eab94527340d..1614d308d0f0 100644 --- a/fs/udf/misc.c +++ b/fs/udf/misc.c @@ -173,13 +173,22 @@ struct genericFormat *udf_get_extendedattr(struct inode *inode, uint32_t type, else offset = le32_to_cpu(eahd->appAttrLocation); - while (offset < iinfo->i_lenEAttr) { + while (offset + sizeof(*gaf) < iinfo->i_lenEAttr) { + uint32_t attrLength; + gaf = (struct genericFormat *)&ea[offset]; + attrLength = le32_to_cpu(gaf->attrLength); + + /* Detect undersized elements and buffer overflows */ + if ((attrLength < sizeof(*gaf)) || + (attrLength > (iinfo->i_lenEAttr - offset))) + break; + if (le32_to_cpu(gaf->attrType) == type && gaf->attrSubtype == subtype) return gaf; else - offset += le32_to_cpu(gaf->attrLength); + offset += attrLength; } } |