6.12-stable review patch. If anyone has any objections, please let me know.
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From: Namjae Jeon linkinjeon@kernel.org
[ Upstream commit aa2a739a75ab6f24ef72fb3fdb9192c081eacf06 ]
parse_dcal() validate num_aces to allocate ace array.
f (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 response buffer size. Use this to check invalid num_aces.
Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/client/cifsacl.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/smb/client/cifsacl.c b/fs/smb/client/cifsacl.c index 1f036169fb582..e36f0e2d7d21e 100644 --- a/fs/smb/client/cifsacl.c +++ b/fs/smb/client/cifsacl.c @@ -778,7 +778,8 @@ static void parse_dacl(struct smb_acl *pdacl, char *end_of_acl, }
/* validate that we do not go past end of acl */ - if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) { + if (end_of_acl < (char *)pdacl + sizeof(struct smb_acl) || + end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) { cifs_dbg(VFS, "ACL too small to parse DACL\n"); return; } @@ -799,8 +800,11 @@ static void parse_dacl(struct smb_acl *pdacl, char *end_of_acl, if (num_aces > 0) { umode_t denied_mode = 0;
- 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; + ppace = kmalloc_array(num_aces, sizeof(struct smb_ace *), GFP_KERNEL); if (!ppace)