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| author | Namjae Jeon <linkinjeon@kernel.org> | 2025-02-12 03:37:57 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-10 15:39:29 +0300 |
| commit | 6edee7c63b93e9a676adc8f01af4715020850cc8 (patch) | |
| tree | 6491ebdffc4424fa0644c9c68d78932eb6f0e26c | |
| parent | da087905e3270e2291c0afae39a28e7d183e5ec3 (diff) | |
| download | linux-6edee7c63b93e9a676adc8f01af4715020850cc8.tar.xz | |
cifs: fix incorrect validation for num_aces field of smb_acl
[ 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>
| -rw-r--r-- | fs/smb/client/cifsacl.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/smb/client/cifsacl.c b/fs/smb/client/cifsacl.c index 1f036169fb58..e36f0e2d7d21 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) |