When a TRANS2 response is split across multiple secondary packets,
coalesce_t2() assembles the payload into the large response buffer.
Two bugs cause SendReceive() to copy only a small fraction of the
assembled buffer into the caller's output buffer.

This manifests when listing a large directory on an SMB1 share
(observed against Windows XP); the first getdents returns only
partial results, and subsequent getdents returns EINVAL.

Bug 1: coalesce_t2() computes the coalesced size as:

  *pdu_len += total_in_src;

cifs_demultiplex_thread() resets *pdu_len to each secondary's own
pdu_length before calling coalesce_t2(), so this accumulates from
the wrong baseline on every secondary after the first.

Bug 2: after reassembly, cifs_demultiplex_thread() sets
mid->resp_buf_size to the final secondary's raw packet size.  This
value is later used as the memcpy length, so only a portion of the
coalesced response is copied.

Fix both by replacing the stale *pdu_len arithmetic with
smbCalcSize(), which reads the BCC field that coalesce_t2()
maintains correctly throughout reassembly.

Fixes: 83bfbd0bb902 ("cifs: Remove the RFC1002 header from smb_hdr")
Cc: stable@vger.kernel.org
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Paulo Alcantara <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs_try_adding_channels() takes a temporary reference to an interface
before dropping iface_lock. If cifs_ses_add_channel() fails, it drops
that reference and then increments iface->weight_fulfilled.

A concurrent interface list refresh can remove the list reference while
channel creation is in progress. In that case, the failure-path
kref_put() releases the last reference and frees iface. Updating
weight_fulfilled afterward then accesses freed memory.

Increment weight_fulfilled before dropping the temporary reference,
keeping iface alive for the final access.

Fixes: 6aac002bcfd5 ("cifs: failure to add channel on iface should bump up weight")
Cc: stable@vger.kernel.org
Signed-off-by: Shuangpeng Bai <shuangpeng.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Example:

  1. mount -t cifs -o compress //localhost/test /mnt
  2. mount | grep cifs
     //localhost/test on /mnt type cifs (..., compress, ...)

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>

Several code paths update the VFS inode size by calling
netfs_resize_file() and cifs_setsize(), but omit the corresponding
fscache_resize_cookie() call, leaving the fscache cookie out of sync
with the actual file size:

  - cifs_file_set_size() in inode.c: server-side truncation via setattr
  - cifs_do_truncate() in file.c: truncates to zero on O_TRUNC open
  - smb2_duplicate_extents() in smb2ops.c: file clone extending EOF
  - smb3_simple_falloc() in smb2ops.c: two branches that extend EOF
    via write-range and SMB2_set_eof respectively

Since every caller of cifs_setsize() must resize the fscache cookie,
add the call to cifs_setsize() itself, consistent with how
truncate_pagecache() is already consolidated there.

Fixes: 70431bfd825d ("cifs: Support fscache indexing rewrite")
Fixes: 93a43155127f ("cifs: Fix missing set of remote_i_size")
Fixes: 110fee6b9bb5 ("smb: client: fix missing timestamp updates with O_TRUNC")
Fixes: 7a06d3b816d7 ("smb/client: emulate small EOF-extending mode 0 fallocate ranges")
Cc: stable@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>
Cc: Paulo Alcantara <pc@manguebit.org>
Cc: Huiwen He <hehuiwen@kylinos.cn>
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Paulo Alcantara <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs_file_set_size() calls cifs_setsize() on success, which calls
i_size_write(), updating i_size to the new value.  The subsequent
check attrs->ia_size != i_size_read() in both cifs_setattr_unix()
and cifs_setattr_nounix() therefore always evaluates false after a
successful cifs_file_set_size(), making the smp_store_release() of
time_last_write dead code.  The truncate path was unprotected against
stale readdir size updates.

Move the stamp to before the cifs_file_set_size() RPC call, guarded
by attrs->ia_size != i_size_read() to exclude no-op same-size
ftruncate(2) calls from stamping time_last_write unnecessarily.

On the error path the stamp remains rather than being restored:
restoring a stale snapshot (prev_tlw) could silently erase a
concurrent _cifsFileInfo_put() close stamp if that close arrived
between the READ_ONCE and the smp_store_release.  readdir is
suppressed until the stamp expires, which extends beyond one acregmax
if the caller retries failed truncations.  stat() is unaffected: the
cifs_revalidate_dentry_attr() path calls cifs_fattr_to_inode() with
from_readdir=false, which bypasses the time_last_write check in
is_size_safe_to_change() entirely and always writes the authoritative
QUERY_INFO result to i_size.

Remove the now-unreachable stamp from the dead block in both functions.

Fixes: e8a8d54c2d50 ("cifs: prevent readdir from changing file size due to stale directory metadata")
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

The time_last_write stamp was scattered across cifs_close(),
smb2_deferred_work_close(), and the three drain functions in misc.c.
This missed the case where background I/O holds the final reference
after userspace close() returns, and required explicit maintenance at
each close-path site.

Move the smp_store_release() into _cifsFileInfo_put(), immediately
before releasing open_file_lock.  This single location covers all
close paths unconditionally: normal close, background I/O dropping the
final reference, deferred close via timer or external drain.  The
spinlock's store-release/load-acquire pairing with is_inode_writable()
already provides the ordering guarantee documented in
is_size_safe_to_change().

Remove the now-redundant stamps from cifs_close(),
smb2_deferred_work_close(), and all six stamp sites in the misc.c
deferred-close drain functions.

Fixes: e8a8d54c2d50 ("cifs: prevent readdir from changing file size due to stale directory metadata")
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Avoid redundant 'strlen()' and use the convenient 'strreplace()'
to simplify 'cifs_fscache_get_super_cookie()'.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>

netfs_alloc_folioq_buffer() may leave a partially allocated folio
queue attached to the caller's buffer pointer when it returns an error.

smb3_init_transform_rq() stores the buffer in the request only after
allocation succeeds, so the common error path cannot free a partial
allocation. Store the buffer pointer before checking the return value so
err_free releases it.

Signed-off-by: Yichong Chen <chenyichong@uniontech.com>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>

The cifs.idmap key type stores its payload length in key->datalen, which
is limited to U16_MAX.  Accepting a larger key payload truncates the
recorded length and can make later users interpret the payload using
inconsistent bounds.

Reject oversized preparsed payloads before allocating or copying them.
This keeps key->datalen consistent with the stored data for both inline
and separately allocated idmap payloads.

Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>

Both branches of the check return the same value, so the check has
no effect. Remove it and return the value directly.

This is the result of running the Coccinelle script from
scripts/coccinelle/misc/cond_return_no_effect.cocci.

Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>