kernel/git/stable/linux.git/fs/dlm/lock.c, branch linux-4.9.y

fs: dlm: handle -EBUSY first in lock arg validation

2022-10-26T11:15:37+00:00

commit 44637ca41d551d409a481117b07fa209b330fca9 upstream. During lock arg validation, first check for -EBUSY cases, then for -EINVAL cases. The -EINVAL checks look at lkb state variables which are not stable when an lkb is busy and would cause an -EBUSY result, e.g. lkb->lkb_grmode. Cc: stable@vger.kernel.org Signed-off-by: Alexander Aring Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman

dlm: fix missing lkb refcount handling

2022-06-14T14:52:34+00:00

commit 1689c169134f4b5a39156122d799b7dca76d8ddb upstream. We always call hold_lkb(lkb) if we increment lkb->lkb_wait_count. So, we always need to call unhold_lkb(lkb) if we decrement lkb->lkb_wait_count. This patch will add missing unhold_lkb(lkb) if we decrement lkb->lkb_wait_count. In case of setting lkb->lkb_wait_count to zero we need to countdown until reaching zero and call unhold_lkb(lkb). The waiters list unhold_lkb(lkb) can be removed because it's done for the last lkb_wait_count decrement iteration as it's done in _remove_from_waiters(). This issue was discovered by a dlm gfs2 test case which use excessively dlm_unlock(LKF_CANCEL) feature. Probably the lkb->lkb_wait_count value never reached above 1 if this feature isn't used and so it was not discovered before. The testcase ended in a rsb on the rsb keep data structure with a refcount of 1 but no lkb was associated with it, which is itself an invalid behaviour. A side effect of that was a condition in which the dlm was sending remove messages in a looping behaviour. With this patch that has not been reproduced. Cc: stable@vger.kernel.org Signed-off-by: Alexander Aring Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman

fs: dlm: filter user dlm messages for kernel locks

2022-01-27T07:47:36+00:00

[ Upstream commit 6c2e3bf68f3e5e5a647aa52be246d5f552d7496d ] This patch fixes the following crash by receiving a invalid message: [ 160.672220] ================================================================== [ 160.676206] BUG: KASAN: user-memory-access in dlm_user_add_ast+0xc3/0x370 [ 160.679659] Read of size 8 at addr 00000000deadbeef by task kworker/u32:13/319 [ 160.681447] [ 160.681824] CPU: 10 PID: 319 Comm: kworker/u32:13 Not tainted 5.14.0-rc2+ #399 [ 160.683472] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.14.0-1.module+el8.6.0+12648+6ede71a5 04/01/2014 [ 160.685574] Workqueue: dlm_recv process_recv_sockets [ 160.686721] Call Trace: [ 160.687310] dump_stack_lvl+0x56/0x6f [ 160.688169] ? dlm_user_add_ast+0xc3/0x370 [ 160.689116] kasan_report.cold.14+0x116/0x11b [ 160.690138] ? dlm_user_add_ast+0xc3/0x370 [ 160.690832] dlm_user_add_ast+0xc3/0x370 [ 160.691502] _receive_unlock_reply+0x103/0x170 [ 160.692241] _receive_message+0x11df/0x1ec0 [ 160.692926] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 160.693700] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 160.694427] ? lock_acquire+0x175/0x400 [ 160.695058] ? do_purge.isra.51+0x200/0x200 [ 160.695744] ? lock_acquired+0x360/0x5d0 [ 160.696400] ? lock_contended+0x6a0/0x6a0 [ 160.697055] ? lock_release+0x21d/0x5e0 [ 160.697686] ? lock_is_held_type+0xe0/0x110 [ 160.698352] ? lock_is_held_type+0xe0/0x110 [ 160.699026] ? ___might_sleep+0x1cc/0x1e0 [ 160.699698] ? dlm_wait_requestqueue+0x94/0x140 [ 160.700451] ? dlm_process_requestqueue+0x240/0x240 [ 160.701249] ? down_write_killable+0x2b0/0x2b0 [ 160.701988] ? do_raw_spin_unlock+0xa2/0x130 [ 160.702690] dlm_receive_buffer+0x1a5/0x210 [ 160.703385] dlm_process_incoming_buffer+0x726/0x9f0 [ 160.704210] receive_from_sock+0x1c0/0x3b0 [ 160.704886] ? dlm_tcp_shutdown+0x30/0x30 [ 160.705561] ? lock_acquire+0x175/0x400 [ 160.706197] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 160.706941] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 160.707681] process_recv_sockets+0x32/0x40 [ 160.708366] process_one_work+0x55e/0xad0 [ 160.709045] ? pwq_dec_nr_in_flight+0x110/0x110 [ 160.709820] worker_thread+0x65/0x5e0 [ 160.710423] ? process_one_work+0xad0/0xad0 [ 160.711087] kthread+0x1ed/0x220 [ 160.711628] ? set_kthread_struct+0x80/0x80 [ 160.712314] ret_from_fork+0x22/0x30 The issue is that we received a DLM message for a user lock but the destination lock is a kernel lock. Note that the address which is trying to derefence is 00000000deadbeef, which is in a kernel lock lkb->lkb_astparam, this field should never be derefenced by the DLM kernel stack. In case of a user lock lkb->lkb_astparam is lkb->lkb_ua (memory is shared by a union field). The struct lkb_ua will be handled by the DLM kernel stack but on a kernel lock it will contain invalid data and ends in most likely crashing the kernel. It can be reproduced with two cluster nodes. node 2: dlm_tool join test echo "862 fooobaar 1 2 1" > /sys/kernel/debug/dlm/test_locks echo "862 3 1" > /sys/kernel/debug/dlm/test_waiters node 1: dlm_tool join test python: foo = DLM(h_cmd=3, o_nextcmd=1, h_nodeid=1, h_lockspace=0x77222027, \ m_type=7, m_flags=0x1, m_remid=0x862, m_result=0xFFFEFFFE) newFile = open("/sys/kernel/debug/dlm/comms/2/rawmsg", "wb") newFile.write(bytes(foo)) Signed-off-by: Alexander Aring Signed-off-by: David Teigland Signed-off-by: Sasha Levin

dlm: memory leaks on error path in dlm_user_request()

2019-01-13T09:03:52+00:00

commit d47b41aceeadc6b58abc9c7c6485bef7cfb75636 upstream. According to comment in dlm_user_request() ua should be freed in dlm_free_lkb() after successful attach to lkb. However ua is attached to lkb not in set_lock_args() but later, inside request_lock(). Fixes 597d0cae0f99 ("[DLM] dlm: user locks") Cc: stable@kernel.org # 2.6.19 Signed-off-by: Vasily Averin Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman

dlm: lost put_lkb on error path in receive_convert() and receive_unlock()

2019-01-13T09:03:52+00:00

commit c0174726c3976e67da8649ac62cae43220ae173a upstream. Fixes 6d40c4a708e0 ("dlm: improve error and debug messages") Cc: stable@kernel.org # 3.5 Signed-off-by: Vasily Averin Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman

dlm: possible memory leak on error path in create_lkb()

2019-01-13T09:03:52+00:00

commit 23851e978f31eda8b2d01bd410d3026659ca06c7 upstream. Fixes 3d6aa675fff9 ("dlm: keep lkbs in idr") Cc: stable@kernel.org # 3.1 Signed-off-by: Vasily Averin Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman

dlm: adopt orphan locks

2014-11-19T20:48:02+00:00

A process may exit, leaving an orphan lock in the lockspace. This adds the capability for another process to acquire the orphan lock. Acquiring the orphan just moves the lock from the orphan list onto the acquiring process's list of locks. An adopting process must specify the resource name and mode of the lock it wants to adopt. If a matching lock is found, the lock is moved to the caller's 's list of locks, and the lkid of the lock is returned like the lkid of a new lock. If an orphan with a different mode is found, then -EAGAIN is returned. If no orphan lock is found on the resource, then -ENOENT is returned. No async completion is used because the result is immediately available. Also, when orphans are purged, allow a zero nodeid to refer to the local nodeid so the caller does not need to look up the local nodeid. Signed-off-by: David Teigland

dlm: use INFO for recovery messages

2014-02-14T17:54:44+00:00

The log messages relating to the progress of recovery are minimal and very often useful. Change these to the KERN_INFO level so they are always available. Signed-off-by: David Teigland

dlm: silence a harmless use after free warning

2014-02-12T21:44:03+00:00

We pass the freed "r" pointer back to the caller. It's harmless but it upsets the static checkers. Signed-off-by: Dan Carpenter Signed-off-by: David Teigland

dlm: Avoid LVB truncation

2013-06-26T16:38:02+00:00

For lockspaces with an LVB length above 64 bytes, avoid truncating the LVB while exchanging it with another node in the cluster. Signed-off-by: Bart Van Assche Signed-off-by: David Teigland