From c422d34a4ad953473b8cc2b232915a4beaf8c3fa Mon Sep 17 00:00:00 2001 From: ChenXiaoSong Date: Sat, 1 Aug 2026 07:55:15 +0000 Subject: [PATCH 1/3] smb/client: show compress mount option 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 Signed-off-by: Steve French --- fs/smb/client/cifsfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c index 1788d93a2522..a1dacc7d8f74 100644 --- a/fs/smb/client/cifsfs.c +++ b/fs/smb/client/cifsfs.c @@ -692,6 +692,8 @@ cifs_show_options(struct seq_file *s, struct dentry *root) seq_puts(s, ",seal"); else if (tcon->ses->server->ignore_signature) seq_puts(s, ",signloosely"); + if (cifs_sb->ctx->compress) + seq_puts(s, ",compress"); if (tcon->nocase) seq_puts(s, ",nocase"); if (tcon->nodelete) From 4986410316b1ae0e63c6ce418e4eb196723626e7 Mon Sep 17 00:00:00 2001 From: Shuangpeng Bai Date: Sat, 1 Aug 2026 20:48:09 -0400 Subject: [PATCH 2/3] smb: client: Fix use-after-free in cifs_try_adding_channels() 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 Signed-off-by: Steve French --- fs/smb/client/sess.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/smb/client/sess.c b/fs/smb/client/sess.c index de2012cc9cf3..7cf7dd104f7c 100644 --- a/fs/smb/client/sess.c +++ b/fs/smb/client/sess.c @@ -233,9 +233,9 @@ int cifs_try_adding_channels(struct cifs_ses *ses) cifs_dbg(VFS, "failed to open extra channel on iface:%pIS rc=%d\n", &iface->sockaddr, rc); - kref_put(&iface->refcount, release_iface); /* failure to add chan should increase weight */ iface->weight_fulfilled++; + kref_put(&iface->refcount, release_iface); continue; } From 26fa4d17c023dbe5427a92d3a7bd9ae1d1e58bc5 Mon Sep 17 00:00:00 2001 From: Frank Sorenson Date: Tue, 4 Aug 2026 14:21:12 -0500 Subject: [PATCH 3/3] smb: client: fix SMB1 TRANS2 multi-response truncation in SendReceive() 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 Reviewed-by: Paulo Alcantara Signed-off-by: Steve French --- fs/smb/client/smb1transport.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/fs/smb/client/smb1transport.c b/fs/smb/client/smb1transport.c index 53abb29fe71b..966f2cf83a51 100644 --- a/fs/smb/client/smb1transport.c +++ b/fs/smb/client/smb1transport.c @@ -260,9 +260,23 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, goto out; if (out_buf) { - *pbytes_returned = resp_iov.iov_len; - if (resp_iov.iov_len) - memcpy(out_buf, resp_iov.iov_base, resp_iov.iov_len); + /* Use smbCalcSize() for both single- and multi-part T2 responses, + * both here and in coalesce_t2(). + */ + unsigned int copy_len; + if (WARN_ON_ONCE(!resp_iov.iov_base)) { + rc = -EIO; + goto out; + } + copy_len = smbCalcSize(resp_iov.iov_base); + if (copy_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) { + cifs_dbg(VFS, "response size %u exceeds buffer\n", + copy_len); + rc = -ENOBUFS; + goto out; + } + *pbytes_returned = copy_len; + memcpy(out_buf, resp_iov.iov_base, copy_len); } out: @@ -386,11 +400,13 @@ coalesce_t2(char *second_buf, struct smb_hdr *target_hdr, unsigned int *pdu_len) } put_bcc(byte_count, target_hdr); - byte_count = *pdu_len; - byte_count += total_in_src; + /* use smbCalcSize() rather than *pdu_len: the demux loop resets + * *pdu_len to each secondary's pdu_length, making it unreliable. + */ + byte_count = smbCalcSize(target_hdr); /* don't allow buffer to overflow */ if (byte_count > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) { - cifs_dbg(FYI, "coalesced BCC exceeds buffer size (%u)\n", + cifs_dbg(FYI, "coalesced size exceeds buffer size (%u)\n", byte_count); return -ENOBUFS; }