From: Namjae Jeon <linkinjeon@kernel.org> mainline inclusion from mainline-v6.12-rc3 commit 1b8b67f3c5e5169535e26efedd3e422172e2db64 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBYED0 CVE: CVE-2025-21994 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- parse_dcal() validate num_aces to allocate posix_ace_state_array. if (num_aces > ULONG_MAX / sizeof(struct smb_ace *)) It is an incorrect validation that we can create an array of size ULONG_MAX. smb_acl has ->size field to calculate actual number of aces in request buffer size. Use this to check invalid num_aces. Reported-by: Igor Leite Ladessa <igor-ladessa@hotmail.com> Tested-by: Igor Leite Ladessa <igor-ladessa@hotmail.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 | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/smb/server/smbacl.c b/fs/smb/server/smbacl.c index da8ed72f335d..109036e2227c 100644 --- a/fs/smb/server/smbacl.c +++ b/fs/smb/server/smbacl.c @@ -398,7 +398,9 @@ static void parse_dacl(struct mnt_idmap *idmap, if (num_aces <= 0) return; - if (num_aces > ULONG_MAX / sizeof(struct smb_ace *)) + if (num_aces > (le16_to_cpu(pdacl->size) - sizeof(struct smb_acl)) / + (offsetof(struct smb_ace, sid) + + offsetof(struct smb_sid, sub_auth) + sizeof(__le16))) return; ret = init_acl_state(&acl_state, num_aces); @@ -432,6 +434,7 @@ static void parse_dacl(struct mnt_idmap *idmap, offsetof(struct smb_sid, sub_auth); if (end_of_acl - acl_base < acl_size || + ppace[i]->sid.num_subauth == 0 || ppace[i]->sid.num_subauth > SID_MAX_SUB_AUTHORITIES || (end_of_acl - acl_base < acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth) || -- 2.39.2