From: Namjae Jeon <linkinjeon@kernel.org> mainline inclusion from mainline-v6.12-rc3 commit d6e13e19063db24f94b690159d0633aaf72a0f03 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IBY448 CVE: CVE-2025-21946 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- If osidoffset, gsidoffset and dacloffset could be greater than smb_ntsd struct size. If it is smaller, It could cause slab-out-of-bounds. And when validating sid, It need to check it included subauth array size. Cc: stable@vger.kernel.org Reported-by: Norbert Szetei <norbert@doyensec.com> Tested-by: Norbert Szetei <norbert@doyensec.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Yongjian Sun <sunyongjian1@huawei.com> --- fs/smb/server/smbacl.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/fs/smb/server/smbacl.c b/fs/smb/server/smbacl.c index 1c9775f1efa5..da8ed72f335d 100644 --- a/fs/smb/server/smbacl.c +++ b/fs/smb/server/smbacl.c @@ -807,6 +807,13 @@ static int parse_sid(struct smb_sid *psid, char *end_of_acl) return -EINVAL; } + if (!psid->num_subauth) + return 0; + + if (psid->num_subauth > SID_MAX_SUB_AUTHORITIES || + end_of_acl < (char *)psid + 8 + sizeof(__le32) * psid->num_subauth) + return -EINVAL; + return 0; } @@ -848,6 +855,9 @@ int parse_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd, pntsd->type = cpu_to_le16(DACL_PRESENT); if (pntsd->osidoffset) { + if (le32_to_cpu(pntsd->osidoffset) < sizeof(struct smb_ntsd)) + return -EINVAL; + rc = parse_sid(owner_sid_ptr, end_of_acl); if (rc) { pr_err("%s: Error %d parsing Owner SID\n", __func__, rc); @@ -863,6 +873,9 @@ int parse_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd, } if (pntsd->gsidoffset) { + if (le32_to_cpu(pntsd->gsidoffset) < sizeof(struct smb_ntsd)) + return -EINVAL; + rc = parse_sid(group_sid_ptr, end_of_acl); if (rc) { pr_err("%s: Error %d mapping Owner SID to gid\n", @@ -884,6 +897,9 @@ int parse_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd, pntsd->type |= cpu_to_le16(DACL_PROTECTED); if (dacloffset) { + if (dacloffset < sizeof(struct smb_ntsd)) + return -EINVAL; + parse_dacl(idmap, dacl_ptr, end_of_acl, owner_sid_ptr, group_sid_ptr, fattr); } -- 2.39.2