linux-stable.git/fs/dlm, branch linux-6.6.y

dlm: prevent NPD when writing a positive value to event_done

2026-07-04T11:42:20+00:00

commit 8e2bad543eca5c25cd02cbc63d72557934d45f13 upstream.

do_uevent returns the value written to event_done. In case it is a
positive value, new_lockspace would undo all the work, and lockspace
would not be set. __dlm_new_lockspace, however, would treat that
positive value as a success due to commit 8511a2728ab8 ("dlm: fix use
count with multiple joins").

Down the line, device_create_lockspace would pass that NULL lockspace to
dlm_find_lockspace_local, leading to a NULL pointer dereference.

Treating such positive values as successes prevents the problem. Given
this has been broken for so long, this is unlikely to break userspace
expectations.

Fixes: 8511a2728ab8 ("dlm: fix use count with multiple joins")
Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: David Teigland 
Signed-off-by: Nazar Kalashnikov 
Signed-off-by: Greg Kroah-Hartman

dlm: check for defined force value in dlm_lockspace_release

2025-10-29T13:07:00+00:00

[ Upstream commit 6af515c9f3ccec3eb8a262ca86bef2c499d07951 ]

Force values over 3 are undefined, so don't treat them as 3.

Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Sasha Levin

dlm: make tcp still work in multi-link env

2025-06-04T12:41:57+00:00

[ Upstream commit 03d2b62208a336a3bb984b9465ef6d89a046ea22 ]

This patch bypasses multi-link errors in TCP mode, allowing dlm
to operate on the first tcp link.

Signed-off-by: Heming Zhao 
Signed-off-by: David Teigland 
Signed-off-by: Sasha Levin

dlm: fix srcu_read_lock() return type to int

2025-02-08T08:51:41+00:00

[ Upstream commit 57cdd1a1cf1464199678f9338049b63fb5d5b41c ]

The return type of srcu_read_lock() is int and not bool. Whereas we
using the ret variable only to evaluate a bool type of
dlm_lowcomms_con_has_addr() to check if an address is already being set.

Fixes: 6f0b0b5d7ae7 ("fs: dlm: remove dlm_node_addrs lookup list")
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Sasha Levin

dlm: fix possible lkb_resource null dereference

2024-12-14T19:00:02+00:00

[ Upstream commit b98333c67daf887c724cd692e88e2db9418c0861 ]

This patch fixes a possible null pointer dereference when this function is
called from request_lock() as lkb->lkb_resource is not assigned yet,
only after validate_lock_args() by calling attach_lkb(). Another issue
is that a resource name could be a non printable bytearray and we cannot
assume to be ASCII coded.

The log functionality is probably never being hit when DLM is used in
normal way and no debug logging is enabled. The null pointer dereference
can only occur on a new created lkb that does not have the resource
assigned yet, it probably never hits the null pointer dereference but we
should be sure that other changes might not change this behaviour and we
actually can hit the mentioned null pointer dereference.

In this patch we just drop the printout of the resource name, the lkb id
is enough to make a possible connection to a resource name if this
exists.

Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Sasha Levin

dlm: fix user space lock decision to copy lvb

2024-06-12T09:11:38+00:00

[ Upstream commit ad191e0eeebf64a60ca2d16ca01a223d2b1dd25e ]

This patch fixes the copy lvb decision for user space lock requests.
Checking dlm_lvb_operations is done earlier, where granted/requested
lock modes are available to use in the matrix.

The decision had been moved to the wrong location, where granted mode
and requested mode where the same, which causes the dlm_lvb_operations
matix to produce the wrong copy decision. For PW or EX requests, the
caller could get invalid lvb data.

Fixes: 61bed0baa4db ("fs: dlm: use a non-static queue for callbacks")
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Sasha Levin

dlm: fix user space lkb refcounting

2024-04-03T13:28:32+00:00

[ Upstream commit 2ab3d705ca5d4f7ea345a21c3da41a447a549649 ]

This patch fixes to check on the right return value if it was the last
callback. The rv variable got overwritten by the return of
copy_result_to_user(). Fixing it by introducing a second variable for
the return value and don't let rv being overwritten.

Cc: stable@vger.kernel.org
Fixes: 61bed0baa4db ("fs: dlm: use a non-static queue for callbacks")
Reported-by: Valentin Vidić 
Closes: https://lore.kernel.org/gfs2/Ze4qSvzGJDt5yxC3@valentin-vidic.from.hr
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Sasha Levin

dlm: use kernel_connect() and kernel_bind()

2024-02-01T00:18:54+00:00

commit e9cdebbe23f1aa9a1caea169862f479ab3fa2773 upstream.

Recent changes to kernel_connect() and kernel_bind() ensure that
callers are insulated from changes to the address parameter made by BPF
SOCK_ADDR hooks. This patch wraps direct calls to ops->connect() and
ops->bind() with kernel_connect() and kernel_bind() to protect callers
in such cases.

Link: https://lore.kernel.org/netdev/9944248dba1bce861375fcce9de663934d933ba9.camel@redhat.com/
Fixes: d74bad4e74ee ("bpf: Hooks for sys_connect")
Fixes: 4fbac77d2d09 ("bpf: Hooks for sys_bind")
Cc: stable@vger.kernel.org
Signed-off-by: Jordan Rife 
Signed-off-by: David Teigland 
Signed-off-by: Greg Kroah-Hartman

dlm: fix format seq ops type 4

2024-01-25T23:35:17+00:00

[ Upstream commit 367e753d5c54a414d82610eb709fe71fda6cf1c3 ]

This patch fixes to set the type 4 format ops in case of table_open4().
It got accidentially changed by commit 541adb0d4d10 ("fs: dlm: debugfs
for queued callbacks") and since them toss debug dumps the same format
as format 5 that are the queued ast callbacks for lkbs.

Fixes: 541adb0d4d10 ("fs: dlm: debugfs for queued callbacks")
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Sasha Levin

fs: dlm: Simplify buffer size computation in dlm_create_debug_file()

2023-11-20T10:59:37+00:00

[ Upstream commit 19b3102c0b5350621e7492281f2be0f071fb7e31 ]

Use sizeof(name) instead of the equivalent, but hard coded,
DLM_LOCKSPACE_LEN + 8.

This is less verbose and more future proof.

Signed-off-by: Christophe JAILLET 
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Sasha Levin