6.1-stable review patch. If anyone has any objections, please let me know.
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From: Norbert Szetei norbert@doyensec.com
commit 0ca6df4f40cf4c32487944aaf48319cb6c25accc upstream.
ksmbd_vfs_stream_write() did not validate whether the write offset (*pos) was within the bounds of the existing stream data length (v_len). If *pos was greater than or equal to v_len, this could lead to an out-of-bounds memory write.
This patch adds a check to ensure *pos is less than v_len before proceeding. If the condition fails, -EINVAL is returned.
Cc: stable@vger.kernel.org Signed-off-by: Norbert Szetei norbert@doyensec.com Acked-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/server/vfs.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -440,6 +440,13 @@ static int ksmbd_vfs_stream_write(struct goto out; }
+ if (v_len <= *pos) { + pr_err("stream write position %lld is out of bounds (stream length: %zd)\n", + *pos, v_len); + err = -EINVAL; + goto out; + } + if (v_len < size) { wbuf = kvzalloc(size, GFP_KERNEL); if (!wbuf) {