| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
pNFS: Fix a deadlock when returning a delegation during open()
Ben Coddington reports seeing a hang in the following stack trace:
0 [ffffd0b50e1774e0] __schedule at ffffffff9ca05415
1 [ffffd0b50e177548] schedule at ffffffff9ca05717
2 [ffffd0b50e177558] bit_wait at ffffffff9ca061e1
3 [ffffd0b50e177568] __wait_on_bit at ffffffff9ca05cfb
4 [ffffd0b50e1775c8] out_of_line_wait_on_bit at ffffffff9ca05ea5
5 [ffffd0b50e177618] pnfs_roc at ffffffffc154207b [nfsv4]
6 [ffffd0b50e1776b8] _nfs4_proc_delegreturn at ffffffffc1506586 [nfsv4]
7 [ffffd0b50e177788] nfs4_proc_delegreturn at ffffffffc1507480 [nfsv4]
8 [ffffd0b50e1777f8] nfs_do_return_delegation at ffffffffc1523e41 [nfsv4]
9 [ffffd0b50e177838] nfs_inode_set_delegation at ffffffffc1524a75 [nfsv4]
10 [ffffd0b50e177888] nfs4_process_delegation at ffffffffc14f41dd [nfsv4]
11 [ffffd0b50e1778a0] _nfs4_opendata_to_nfs4_state at ffffffffc1503edf [nfsv4]
12 [ffffd0b50e1778c0] _nfs4_open_and_get_state at ffffffffc1504e56 [nfsv4]
13 [ffffd0b50e177978] _nfs4_do_open at ffffffffc15051b8 [nfsv4]
14 [ffffd0b50e1779f8] nfs4_do_open at ffffffffc150559c [nfsv4]
15 [ffffd0b50e177a80] nfs4_atomic_open at ffffffffc15057fb [nfsv4]
16 [ffffd0b50e177ad0] nfs4_file_open at ffffffffc15219be [nfsv4]
17 [ffffd0b50e177b78] do_dentry_open at ffffffff9c09e6ea
18 [ffffd0b50e177ba8] vfs_open at ffffffff9c0a082e
19 [ffffd0b50e177bd0] dentry_open at ffffffff9c0a0935
The issue is that the delegreturn is being asked to wait for a layout
return that cannot complete because a state recovery was initiated. The
state recovery cannot complete until the open() finishes processing the
delegations it was given.
The solution is to propagate the existing flags that indicate a
non-blocking call to the function pnfs_roc(), so that it knows not to
wait in this situation. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: do not strictly require dirty metadata threshold for metadata writepages
[BUG]
There is an internal report that over 1000 processes are
waiting at the io_schedule_timeout() of balance_dirty_pages(), causing
a system hang and trigger a kernel coredump.
The kernel is v6.4 kernel based, but the root problem still applies to
any upstream kernel before v6.18.
[CAUSE]
From Jan Kara for his wisdom on the dirty page balance behavior first.
This cgroup dirty limit was what was actually playing the role here
because the cgroup had only a small amount of memory and so the dirty
limit for it was something like 16MB.
Dirty throttling is responsible for enforcing that nobody can dirty
(significantly) more dirty memory than there's dirty limit. Thus when
a task is dirtying pages it periodically enters into balance_dirty_pages()
and we let it sleep there to slow down the dirtying.
When the system is over dirty limit already (either globally or within
a cgroup of the running task), we will not let the task exit from
balance_dirty_pages() until the number of dirty pages drops below the
limit.
So in this particular case, as I already mentioned, there was a cgroup
with relatively small amount of memory and as a result with dirty limit
set at 16MB. A task from that cgroup has dirtied about 28MB worth of
pages in btrfs btree inode and these were practically the only dirty
pages in that cgroup.
So that means the only way to reduce the dirty pages of that cgroup is
to writeback the dirty pages of btrfs btree inode, and only after that
those processes can exit balance_dirty_pages().
Now back to the btrfs part, btree_writepages() is responsible for
writing back dirty btree inode pages.
The problem here is, there is a btrfs internal threshold that if the
btree inode's dirty bytes are below the 32M threshold, it will not
do any writeback.
This behavior is to batch as much metadata as possible so we won't write
back those tree blocks and then later re-COW them again for another
modification.
This internal 32MiB is higher than the existing dirty page size (28MiB),
meaning no writeback will happen, causing a deadlock between btrfs and
cgroup:
- Btrfs doesn't want to write back btree inode until more dirty pages
- Cgroup/MM doesn't want more dirty pages for btrfs btree inode
Thus any process touching that btree inode is put into sleep until
the number of dirty pages is reduced.
Thanks Jan Kara a lot for the analysis of the root cause.
[ENHANCEMENT]
Since kernel commit b55102826d7d ("btrfs: set AS_KERNEL_FILE on the
btree_inode"), btrfs btree inode pages will only be charged to the root
cgroup which should have a much larger limit than btrfs' 32MiB
threshold.
So it should not affect newer kernels.
But for all current LTS kernels, they are all affected by this problem,
and backporting the whole AS_KERNEL_FILE may not be a good idea.
Even for newer kernels I still think it's a good idea to get
rid of the internal threshold at btree_writepages(), since for most cases
cgroup/MM has a better view of full system memory usage than btrfs' fixed
threshold.
For internal callers using btrfs_btree_balance_dirty() since that
function is already doing internal threshold check, we don't need to
bother them.
But for external callers of btree_writepages(), just respect their
requests and write back whatever they want, ignoring the internal
btrfs threshold to avoid such deadlock on btree inode dirty page
balancing. |
| In the Linux kernel, the following vulnerability has been resolved:
ipvlan: Make the addrs_lock be per port
Make the addrs_lock be per port, not per ipvlan dev.
Initial code seems to be written in the assumption,
that any address change must occur under RTNL.
But it is not so for the case of IPv6. So
1) Introduce per-port addrs_lock.
2) It was needed to fix places where it was forgotten
to take lock (ipvlan_open/ipvlan_close)
This appears to be a very minor problem though.
Since it's highly unlikely that ipvlan_add_addr() will
be called on 2 CPU simultaneously. But nevertheless,
this could cause:
1) False-negative of ipvlan_addr_busy(): one interface
iterated through all port->ipvlans + ipvlan->addrs
under some ipvlan spinlock, and another added IP
under its own lock. Though this is only possible
for IPv6, since looks like only ipvlan_addr6_event() can be
called without rtnl_lock.
2) Race since ipvlan_ht_addr_add(port) is called under
different ipvlan->addrs_lock locks
This should not affect performance, since add/remove IP
is a rare situation and spinlock is not taken on fast
paths. |
| ZoneAlarm and ZoneAlarm Pro allows a local attacker to cause a denial of service by running a trojan to initialize a ZoneAlarm mutex object which prevents ZoneAlarm from starting. |
| Heysoft EventSave 5.1 and 5.2 and Heysoft EventSave+ 5.1 and 5.2 does not check whether the log file can be written to, which allows attackers to prevent events from being recorded by opening the log file using an application such as Microsoft's Event Viewer. |
| Array index overflow in the xfrm_sk_policy_insert function in xfrm_user.c in Linux kernel 2.6 allows local users to cause a denial of service (oops or deadlock) and possibly execute arbitrary code via a p->dir value that is larger than XFRM_POLICY_OUT, which is used as an index in the sock->sk_policy array. |
| dump 0.4 b10 through b29 allows local users to cause a denial of service (execution prevention) by using flock() to lock the /etc/dumpdates file. |
| qpopper POP server creates lock files with predictable names, which allows local users to cause a denial of service for other users (lack of mail access) by creating lock files for other mail boxes. |
| mod_cgi in Apache 2.0.39 and 2.0.40 allows local users and possibly remote attackers to cause a denial of service (hang and memory consumption) by causing a CGI script to send a large amount of data to stderr, which results in a read/write deadlock between httpd and the CGI script. |
| Apache 1.4.x before 1.3.30, and 2.0.x before 2.0.49, when using multiple listening sockets on certain platforms, allows remote attackers to cause a denial of service (blocked new connections) via a "short-lived connection on a rarely-accessed listening socket." |
| Concurrent Versions Software (CVS) uses predictable temporary file names for locking, which allows local users to cause a denial of service by creating the lock directory before it is created for use by a legitimate CVS user. |
| Linux SCTP (lksctp) before 2.6.17 allows remote attackers to cause a denial of service (deadlock) via a large number of small messages to a receiver application that cannot process the messages quickly enough, which leads to "spillover of the receive buffer." |
| The Server Message Block (SMB) driver (MRXSMB.SYS) in Microsoft Windows 2000 SP4, XP SP1 and SP2, and Server 2003 SP1 and earlier allows local users to cause a denial of service (hang) by calling the MrxSmbCscIoctlCloseForCopyChunk with the file handle of the shadow device, which results in a deadlock, aka the "SMB Invalid Handle Vulnerability." |
| Windows 2000 allows local users to prevent the application of new group policy settings by opening Group Policy files with exclusive-read access. |
| tip on multiple BSD-based operating systems allows local users to cause a denial of service (execution prevention) by using flock() to lock the /var/log/acculog file. |
| The handle_stop_signal function in signal.c in Linux kernel 2.6.11 up to other versions before 2.6.13 and 2.6.12.6 allows local users to cause a denial of service (deadlock) by sending a SIGKILL to a real-time threaded process while it is performing a core dump. |
| Race condition in Linux 2.6, when threads are sharing memory mapping via CLONE_VM (such as linuxthreads and vfork), might allow local users to cause a denial of service (deadlock) by triggering a core dump while waiting for a thread that has just performed an exec. |
| In the Linux kernel, the following vulnerability has been resolved:
Revert "f2fs: block cache/dio write during f2fs_enable_checkpoint()"
This reverts commit 196c81fdd438f7ac429d5639090a9816abb9760a.
Original patch may cause below deadlock, revert it.
write remount
- write_begin
- lock_page --- lock A
- prepare_write_begin
- f2fs_map_lock
- f2fs_enable_checkpoint
- down_write(cp_enable_rwsem) --- lock B
- sync_inode_sb
- writepages
- lock_page --- lock A
- down_read(cp_enable_rwsem) --- lock A |
| A Zigbee Radio Co-Processor (RCP), which is using SiLabs EmberZNet Zigbee stack, was unable to send messages to the host system (CPCd) due to heavy Zigbee traffic, resulting in a Denial of Service (DoS) attack, Only hard reset will bring the device to normal operation |
| Improper locking for some Intel(R) TDX Module firmware before version 1.5.13 may allow a privileged user to potentially enable escalation of privilege via local access. |
