linux-stable.git/fs, branch v6.14.3

fuse: {io-uring} Fix a possible req cancellation race

2025-04-20T08:23:13+00:00

commit 09098e62e4be8f0755e58d6078aaf27cbd9a3a8d upstream.

task-A (application) might be in request_wait_answer and
try to remove the request when it has FR_PENDING set.

task-B (a fuse-server io-uring task) might handle this
request with FUSE_IO_URING_CMD_COMMIT_AND_FETCH, when
fetching the next request and accessed the req from
the pending list in fuse_uring_ent_assign_req().
That code path was not protected by fiq->lock and so
might race with task-A.

For scaling reasons we better don't use fiq->lock, but
add a handler to remove canceled requests from the queue.

This also removes usage of fiq->lock from
fuse_uring_add_req_to_ring_ent() altogether, as it was
there just to protect against this race and incomplete.

Also added is a comment why FR_PENDING is not cleared.

Fixes: c090c8abae4b ("fuse: Add io-uring sqe commit and fetch support")
Cc:  # v6.14
Reported-by: Joanne Koong 
Closes: https://lore.kernel.org/all/CAJnrk1ZgHNb78dz-yfNTpxmW7wtT88A=m-zF0ZoLXKLUHRjNTw@mail.gmail.com/
Signed-off-by: Bernd Schubert 
Reviewed-by: Joanne Koong 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

dlm: fix error if active rsb is not hashed

2025-04-20T08:23:12+00:00

commit a3672304abf2a847ac0c54c84842c64c5bfba279 upstream.

If an active rsb is not hashed anymore and this could occur because we
releases and acquired locks we need to signal the followed code that
the lookup failed. Since the lookup was successful, but it isn't part of
the rsb hash anymore we need to signal it by setting error to -EBADR as
dlm_search_rsb_tree() does it.

Cc: stable@vger.kernel.org
Fixes: 5be323b0c64d ("dlm: move dlm_search_rsb_tree() out of lock")
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Greg Kroah-Hartman

dlm: fix error if inactive rsb is not hashed

2025-04-20T08:23:12+00:00

commit 94e6e889a786dd16542fc8f2a45405fa13e3bbb5 upstream.

If an inactive rsb is not hashed anymore and this could occur because we
releases and acquired locks we need to signal the followed code that the
lookup failed. Since the lookup was successful, but it isn't part of the
rsb hash anymore we need to signal it by setting error to -EBADR as
dlm_search_rsb_tree() does it.

Cc: stable@vger.kernel.org
Fixes: 01fdeca1cc2d ("dlm: use rcu to avoid an extra rsb struct lookup")
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Greg Kroah-Hartman

cifs: Ensure that all non-client-specific reparse points are processed by the server

2025-04-20T08:23:11+00:00

commit 6f8a394aa952257575910d57cf0a63627fa949a2 upstream.

Fix regression in mounts to e.g. onedrive shares.

Generally, reparse points are processed by the SMB server during the
SMB OPEN request, but there are few reparse points which do not have
OPEN-like meaning for the SMB server and has to be processed by the SMB
client. Those are symlinks and special files (fifo, socket, block, char).

For Linux SMB client, it is required to process also name surrogate reparse
points as they represent another entity on the SMB server system. Linux
client will mark them as separate mount points. Examples of name surrogate
reparse points are NTFS junction points (e.g. created by the "mklink" tool
on Windows servers).

So after processing the name surrogate reparse points, clear the
-EOPNOTSUPP error code returned from the parse_reparse_point() to let SMB
server to process reparse points.

And remove printing misleading error message "unhandled reparse tag:" as
reparse points are handled by SMB server and hence unhandled fact is normal
operation.

Fixes: cad3fc0a4c8c ("cifs: Throw -EOPNOTSUPP error on unsupported reparse point type from parse_reparse_point()")
Fixes: b587fd128660 ("cifs: Treat unhandled directory name surrogate reparse points as mount directory nodes")
Cc: stable@vger.kernel.org
Reported-by: Junwen Sun 
Tested-by: Junwen Sun 
Signed-off-by: Pali Rohár 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

cifs: fix integer overflow in match_server()

2025-04-20T08:23:10+00:00

commit 2510859475d7f46ed7940db0853f3342bf1b65ee upstream.

The echo_interval is not limited in any way during mounting,
which makes it possible to write a large number to it. This can
cause an overflow when multiplying ctx->echo_interval by HZ in
match_server().

Add constraints for echo_interval to smb3_fs_context_parse_param().

Found by Linux Verification Center (linuxtesting.org) with Svace.

Fixes: adfeb3e00e8e1 ("cifs: Make echo interval tunable")
Cc: stable@vger.kernel.org
Signed-off-by: Roman Smirnov 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

cifs: avoid NULL pointer dereference in dbg call

2025-04-20T08:23:10+00:00

commit b4885bd5935bb26f0a414ad55679a372e53f9b9b upstream.

cifs_server_dbg() implies server to be non-NULL so
move call under condition to avoid NULL pointer dereference.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: e79b0332ae06 ("cifs: ignore cached share root handle closing errors")
Cc: stable@vger.kernel.org
Signed-off-by: Alexandra Diupina 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

CIFS: Propagate min offload along with other parameters from primary to secondary channels.

2025-04-20T08:23:10+00:00

commit 1821e90be08e7d4a54cd167dd818d80d06e064e9 upstream.

In a multichannel setup, it was observed that a few fields were not being
copied over to the secondary channels, which impacted performance in cases
where these options were relevant but not properly synchronized. To address
this, this patch introduces copying the following parameters from the
primary channel to the secondary channels:

- min_offload
- compression.requested
- dfs_conn
- ignore_signature
- leaf_fullpath
- noblockcnt
- retrans
- sign

By copying these parameters, we ensure consistency across channels and
prevent performance degradation due to missing or outdated settings.

Cc: stable@vger.kernel.org
Signed-off-by: Aman 
Reviewed-by: Paulo Alcantara (Red Hat) 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

mm/userfaultfd: fix release hang over concurrent GUP

2025-04-20T08:23:08+00:00

commit fe4cdc2c4e248f48de23bc778870fd71e772a274 upstream.

This patch should fix a possible userfaultfd release() hang during
concurrent GUP.

This problem was initially reported by Dimitris Siakavaras in July 2023
[1] in a firecracker use case.  Firecracker has a separate process
handling page faults remotely, and when the process releases the
userfaultfd it can race with a concurrent GUP from KVM trying to fault in
a guest page during the secondary MMU page fault process.

A similar problem was reported recently again by Jinjiang Tu in March 2025
[2], even though the race happened this time with a mlockall() operation,
which does GUP in a similar fashion.

In 2017, commit 656710a60e36 ("userfaultfd: non-cooperative: closing the
uffd without triggering SIGBUS") was trying to fix this issue.  AFAIU,
that fixes well the fault paths but may not work yet for GUP.  In GUP, the
issue is NOPAGE will be almost treated the same as "page fault resolved"
in faultin_page(), then the GUP will follow page again, seeing page
missing, and it'll keep going into a live lock situation as reported.

This change makes core mm return RETRY instead of NOPAGE for both the GUP
and fault paths, proactively releasing the mmap read lock.  This should
guarantee the other release thread make progress on taking the write lock
and avoid the live lock even for GUP.

When at it, rearrange the comments to make sure it's uptodate.

[1] https://lore.kernel.org/r/79375b71-db2e-3e66-346b-254c90d915e2@cslab.ece.ntua.gr
[2] https://lore.kernel.org/r/20250307072133.3522652-1-tujinjiang@huawei.com

Link: https://lkml.kernel.org/r/20250312145131.1143062-1-peterx@redhat.com
Signed-off-by: Peter Xu 
Cc: Andrea Arcangeli 
Cc: Mike Rapoport (IBM) 
Cc: Axel Rasmussen 
Cc: Jinjiang Tu 
Cc: Dimitris Siakavaras 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

btrfs: zoned: fix zone finishing with missing devices

2025-04-20T08:23:06+00:00

commit 35fec1089ebb5617f85884d3fa6a699ce6337a75 upstream.

If do_zone_finish() is called with a filesystem that has missing devices
(e.g. a RAID file system mounted in degraded mode) it is accessing the
btrfs_device::zone_info pointer, which will not be set if the device
in question is missing.

Check if the device is present (by checking if it has a valid block device
pointer associated) and if not, skip zone finishing for it.

Fixes: 4dcbb8ab31c1 ("btrfs: zoned: make zone finishing multi stripe capable")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Naohiro Aota 
Reviewed-by: Anand Jain 
Signed-off-by: Johannes Thumshirn 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: zoned: fix zone activation with missing devices

2025-04-20T08:23:06+00:00

commit 2bbc4a45e5eb6b868357c1045bf6f38f6ba576e0 upstream.

If btrfs_zone_activate() is called with a filesystem that has missing
devices (e.g. a RAID file system mounted in degraded mode) it is accessing
the btrfs_device::zone_info pointer, which will not be set if the device in
question is missing.

Check if the device is present (by checking if it has a valid block
device pointer associated) and if not, skip zone activation for it.

Fixes: f9a912a3c45f ("btrfs: zoned: make zone activation multi stripe capable")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Naohiro Aota 
Reviewed-by: Anand Jain 
Signed-off-by: Johannes Thumshirn 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman