Security Vulnerabilities - CVEs Published In May 2024
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix race when detecting delalloc ranges during fiemap
For fiemap we recently stopped locking the target extent range for the
whole duration of the fiemap call, in order to avoid a deadlock in a
scenario where the fiemap buffer happens to be a memory mapped range of
the same file. This use case is very unlikely to be useful in practice but
it may be triggered by fuzz testing (syzbot, etc).
This however introduced a race that makes us miss delalloc ranges for
file regions that are currently holes, so the caller of fiemap will not
be aware that there's data for some file regions. This can be quite
serious for some use cases - for example in coreutils versions before 9.0,
the cp program used fiemap to detect holes and data in the source file,
copying only regions with data (extents or delalloc) from the source file
to the destination file in order to preserve holes (see the documentation
for its --sparse command line option). This means that if cp was used
with a source file that had delalloc in a hole, the destination file could
end up without that data, which is effectively a data loss issue, if it
happened to hit the race described below.
The race happens like this:
1) Fiemap is called, without the FIEMAP_FLAG_SYNC flag, for a file that
has delalloc in the file range [64M, 65M[, which is currently a hole;
2) Fiemap locks the inode in shared mode, then starts iterating the
inode's subvolume tree searching for file extent items, without having
the whole fiemap target range locked in the inode's io tree - the
change introduced recently by commit b0ad381fa769 ("btrfs: fix
deadlock with fiemap and extent locking"). It only locks ranges in
the io tree when it finds a hole or prealloc extent since that
commit;
3) Note that fiemap clones each leaf before using it, and this is to
avoid deadlocks when locking a file range in the inode's io tree and
the fiemap buffer is memory mapped to some file, because writing
to the page with btrfs_page_mkwrite() will wait on any ordered extent
for the page's range and the ordered extent needs to lock the range
and may need to modify the same leaf, therefore leading to a deadlock
on the leaf;
4) While iterating the file extent items in the cloned leaf before
finding the hole in the range [64M, 65M[, the delalloc in that range
is flushed and its ordered extent completes - meaning the corresponding
file extent item is in the inode's subvolume tree, but not present in
the cloned leaf that fiemap is iterating over;
5) When fiemap finds the hole in the [64M, 65M[ range by seeing the gap in
the cloned leaf (or a file extent item with disk_bytenr == 0 in case
the NO_HOLES feature is not enabled), it will lock that file range in
the inode's io tree and then search for delalloc by checking for the
EXTENT_DELALLOC bit in the io tree for that range and ordered extents
(with btrfs_find_delalloc_in_range()). But it finds nothing since the
delalloc in that range was already flushed and the ordered extent
completed and is gone - as a result fiemap will not report that there's
delalloc or an extent for the range [64M, 65M[, so user space will be
mislead into thinking that there's a hole in that range.
This could actually be sporadically triggered with test case generic/094
from fstests, which reports a missing extent/delalloc range like this:
generic/094 2s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//generic/094.out.bad)
--- tests/generic/094.out 2020-06-10 19:29:03.830519425 +0100
+++ /home/fdmanana/git/hub/xfstests/results//generic/094.out.bad 2024-02-28 11:00:00.381071525 +0000
@@ -1,3 +1,9 @@
QA output created by 094
fiemap run with sync
fiemap run without sync
+ERROR: couldn't find extent at 7
+map is 'HHDDHPPDPHPH'
+logical: [ 5.. 6] phys:
---truncated---
CVSS Score
4.7
EPSS Score
0.002
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: fix some memleaks in gssx_dec_option_array
The creds and oa->data need to be freed in the error-handling paths after
their allocation. So this patch add these deallocations in the
corresponding paths.
CVSS Score
9.8
EPSS Score
0.01
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
pstore: inode: Only d_invalidate() is needed
Unloading a modular pstore backend with records in pstorefs would
trigger the dput() double-drop warning:
WARNING: CPU: 0 PID: 2569 at fs/dcache.c:762 dput.part.0+0x3f3/0x410
Using the combo of d_drop()/dput() (as mentioned in
Documentation/filesystems/vfs.rst) isn't the right approach here, and
leads to the reference counting problem seen above. Use d_invalidate()
and update the code to not bother checking for error codes that can
never happen.
---
CVSS Score
7.8
EPSS Score
0.002
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
ipv6: mcast: remove one synchronize_net() barrier in ipv6_mc_down()
As discussed in the past (commit 2d3916f31891 ("ipv6: fix skb drops
in igmp6_event_query() and igmp6_event_report()")) I think the
synchronize_net() call in ipv6_mc_down() is not needed.
Under load, synchronize_net() can last between 200 usec and 5 ms.
KASAN seems to agree as well.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
wifi: wilc1000: do not realloc workqueue everytime an interface is added
Commit 09ed8bfc5215 ("wilc1000: Rename workqueue from "WILC_wq" to
"NETDEV-wq"") moved workqueue creation in wilc_netdev_ifc_init in order to
set the interface name in the workqueue name. However, while the driver
needs only one workqueue, the wilc_netdev_ifc_init is called each time we
add an interface over a phy, which in turns overwrite the workqueue with a
new one. This can be observed with the following commands:
for i in $(seq 0 10)
do
iw phy phy0 interface add wlan1 type managed
iw dev wlan1 del
done
ps -eo pid,comm|grep wlan
39 kworker/R-wlan0
98 kworker/R-wlan1
102 kworker/R-wlan1
105 kworker/R-wlan1
108 kworker/R-wlan1
111 kworker/R-wlan1
114 kworker/R-wlan1
117 kworker/R-wlan1
120 kworker/R-wlan1
123 kworker/R-wlan1
126 kworker/R-wlan1
129 kworker/R-wlan1
Fix this leakage by putting back hif_workqueue allocation in
wilc_cfg80211_init. Regarding the workqueue name, it is indeed relevant to
set it lowercase, however it is not attached to a specific netdev, so
enforcing netdev name in the name is not so relevant. Still, enrich the
name with the wiphy name to make it clear which phy is using the workqueue.
CVSS Score
5.5
EPSS Score
0.003
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
nvme: host: fix double-free of struct nvme_id_ns in ns_update_nuse()
When nvme_identify_ns() fails, it frees the pointer to the struct
nvme_id_ns before it returns. However, ns_update_nuse() calls kfree()
for the pointer even when nvme_identify_ns() fails. This results in
KASAN double-free, which was observed with blktests nvme/045 with
proposed patches [1] on the kernel v6.8-rc7. Fix the double-free by
skipping kfree() when nvme_identify_ns() fails.
CVSS Score
7.8
EPSS Score
0.003
Published
2024-05-01
IBM WebSphere Automation 1.7.0 is vulnerable to cross-site scripting. This vulnerability allows users to embed arbitrary JavaScript code in the Web UI thus altering the intended functionality potentially leading to credentials disclosure within a trusted session. IBM X-Force ID: 285648.
CVSS Score
4.4
EPSS Score
0.004
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7925e: fix use-after-free in free_irq()
From commit a304e1b82808 ("[PATCH] Debug shared irqs"), there is a test
to make sure the shared irq handler should be able to handle the unexpected
event after deregistration. For this case, let's apply MT76_REMOVED flag to
indicate the device was removed and do not run into the resource access
anymore.
CVSS Score
7.8
EPSS Score
0.003
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
libbpf: Use OPTS_SET() macro in bpf_xdp_query()
When the feature_flags and xdp_zc_max_segs fields were added to the libbpf
bpf_xdp_query_opts, the code writing them did not use the OPTS_SET() macro.
This causes libbpf to write to those fields unconditionally, which means
that programs compiled against an older version of libbpf (with a smaller
size of the bpf_xdp_query_opts struct) will have its stack corrupted by
libbpf writing out of bounds.
The patch adding the feature_flags field has an early bail out if the
feature_flags field is not part of the opts struct (via the OPTS_HAS)
macro, but the patch adding xdp_zc_max_segs does not. For consistency, this
fix just changes the assignments to both fields to use the OPTS_SET()
macro.
CVSS Score
7.8
EPSS Score
0.003
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: brcmstb-avs-cpufreq: add check for cpufreq_cpu_get's return value
cpufreq_cpu_get may return NULL. To avoid NULL-dereference check it
and return 0 in case of error.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
CVSS Score
5.5
EPSS Score
0.003
Published
2024-05-01