6.1-stable review patch. If anyone has any objections, please let me know.
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From: Eugene Korenevsky ekorenevsky@aliyun.com
commit 6447b0e355562a1ff748c4a2ffb89aae7e84d2c9 upstream.
Malicious SMB server can send invalid reply to FSCTL_DFS_GET_REFERRALS
- reply smaller than sizeof(struct get_dfs_referral_rsp) - reply with number of referrals smaller than NumberOfReferrals in the header
Processing of such replies will cause oob.
Return -EINVAL error on such replies to prevent oob-s.
Signed-off-by: Eugene Korenevsky ekorenevsky@aliyun.com Cc: stable@vger.kernel.org Suggested-by: Nathan Chancellor nathan@kernel.org Acked-by: Paulo Alcantara (Red Hat) pc@manguebit.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/client/misc.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
--- a/fs/smb/client/misc.c +++ b/fs/smb/client/misc.c @@ -866,6 +866,14 @@ parse_dfs_referrals(struct get_dfs_refer char *data_end; struct dfs_referral_level_3 *ref;
+ if (rsp_size < sizeof(*rsp)) { + cifs_dbg(VFS | ONCE, + "%s: header is malformed (size is %u, must be %zu)\n", + __func__, rsp_size, sizeof(*rsp)); + rc = -EINVAL; + goto parse_DFS_referrals_exit; + } + *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
if (*num_of_nodes < 1) { @@ -874,6 +882,15 @@ parse_dfs_referrals(struct get_dfs_refer rc = -EINVAL; goto parse_DFS_referrals_exit; } + + if (sizeof(*rsp) + *num_of_nodes * sizeof(REFERRAL3) > rsp_size) { + cifs_dbg(VFS | ONCE, + "%s: malformed buffer (size is %u, must be at least %zu)\n", + __func__, rsp_size, + sizeof(*rsp) + *num_of_nodes * sizeof(REFERRAL3)); + rc = -EINVAL; + goto parse_DFS_referrals_exit; + }
ref = (struct dfs_referral_level_3 *) &(rsp->referrals); if (ref->VersionNumber != cpu_to_le16(3)) {