]> git.ipfire.org Git - thirdparty/linux.git/commit
ksmbd: fix durable reconnect error path file lifetime
authorJunyi Liu <moss80199@gmail.com>
Mon, 18 May 2026 14:27:19 +0000 (23:27 +0900)
committerSteve French <stfrench@microsoft.com>
Thu, 21 May 2026 23:18:49 +0000 (18:18 -0500)
commit3515503322f4819277091839eed46b695096aca5
tree3ba1480aea9cefbdbd9b26aaa2389a28c437ba63
parent1a2ab0feaa23147e347b4d4cb79cb3fc392118eb
ksmbd: fix durable reconnect error path file lifetime

After a durable reconnect succeeds, ksmbd_reopen_durable_fd() republishes
the same ksmbd_file into the session volatile-id table. If smb2_open()
then takes a later error path, cleanup first calls ksmbd_fd_put(work, fp)
and then unconditionally calls ksmbd_put_durable_fd(dh_info.fp).

In this case fp and dh_info.fp are the same object. The first put drops the
reconnect lookup reference, but the final durable put can run
__ksmbd_close_fd(NULL, fp). Because the final close is not session-aware,
it can free the file object without removing the volatile-id entry that was
just published into the session table.

Use the session-aware put for the final reconnect drop when the reconnect
had already succeeded and the error path is cleaning up the republished
file. Earlier reconnect failures, before fp is assigned to dh_info.fp, keep
using the durable-only put path.

Fixes: 1baff47b81f9 ("ksmbd: fix use-after-free in smb2_open during durable reconnect")
Signed-off-by: Junyi Liu <moss80199@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
fs/smb/server/smb2pdu.c