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 1f4bbedd4e5a69b01cde2cc21d01151ab2d0884f ]
If there is no stream data in file, v_len is zero. So, If position(*pos) is zero, stream write will fail due to stream write position validation check. This patch reorganize stream write position validation.
Fixes: 0ca6df4f40cf ("ksmbd: prevent out-of-bounds stream writes by validating *pos") 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/server/vfs.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c index e059316be36fd..59ae63ab86857 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -426,10 +426,15 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos, ksmbd_debug(VFS, "write stream data pos : %llu, count : %zd\n", *pos, count);
+ if (*pos >= XATTR_SIZE_MAX) { + pr_err("stream write position %lld is out of bounds\n", *pos); + return -EINVAL; + } + size = *pos + count; if (size > XATTR_SIZE_MAX) { size = XATTR_SIZE_MAX; - count = (*pos + count) - XATTR_SIZE_MAX; + count = XATTR_SIZE_MAX - *pos; }
v_len = ksmbd_vfs_getcasexattr(idmap, @@ -443,13 +448,6 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos, 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, KSMBD_DEFAULT_GFP); if (!wbuf) {