The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x d10c77873ba1e9e6b91905018e29e196fd5f863d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2024010241-define-gangly-9bf9@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: d10c77873ba1 ("ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From d10c77873ba1e9e6b91905018e29e196fd5f863d Mon Sep 17 00:00:00 2001 From: Namjae Jeon <linkinjeon@xxxxxxxxxx> Date: Wed, 20 Dec 2023 15:52:11 +0900 Subject: [PATCH] ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16() If ->NameOffset/Length is bigger than ->CreateContextsOffset/Length, ksmbd_check_message doesn't validate request buffer it correctly. So slab-out-of-bounds warning from calling smb_strndup_from_utf16() in smb2_open() could happen. If ->NameLength is non-zero, Set the larger of the two sums (Name and CreateContext size) as the offset and length of the data area. Reported-by: Yang Chaoming <lometsj@xxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> diff --git a/fs/smb/server/smb2misc.c b/fs/smb/server/smb2misc.c index 23bd3d1209df..03dded29a980 100644 --- a/fs/smb/server/smb2misc.c +++ b/fs/smb/server/smb2misc.c @@ -106,16 +106,25 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len, break; case SMB2_CREATE: { + unsigned short int name_off = + le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset); + unsigned short int name_len = + le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength); + if (((struct smb2_create_req *)hdr)->CreateContextsLength) { *off = le32_to_cpu(((struct smb2_create_req *) hdr)->CreateContextsOffset); *len = le32_to_cpu(((struct smb2_create_req *) hdr)->CreateContextsLength); - break; + if (!name_len) + break; + + if (name_off + name_len < (u64)*off + *len) + break; } - *off = le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset); - *len = le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength); + *off = name_off; + *len = name_len; break; } case SMB2_QUERY_INFO:
