In the Linux kernel, the following vulnerability has been resolved:
xfs: delete attr leaf freemap entries when empty
Back in commit 2a2b5932db6758 ("xfs: fix attr leaf header freemap.size
underflow"), Brian Foster observed that it's possible for a small
freemap at the end of the end of the xattr entries array to experience
a size underflow when subtracting the space consumed by an expansion of
the entries array. There are only three freemap entries, which means
that it is not a complete index of all free space in the leaf block.
This code can leave behind a zero-length freemap entry with a nonzero
base. Subsequent setxattr operations can increase the base up to the
point that it overlaps with another freemap entry. This isn't in and of
itself a problem because the code in _leaf_add that finds free space
ignores any freemap entry with zero size.
However, there's another bug in the freemap update code in _leaf_add,
which is that it fails to update a freemap entry that begins midway
through the xattr entry that was just appended to the array. That can
result in the freemap containing two entries with the same base but
different sizes (0 for the "pushed-up" entry, nonzero for the entry
that's actually tracking free space). A subsequent _leaf_add can then
allocate xattr namevalue entries on top of the entries array, leading to
data loss. But fixing that is for later.
For now, eliminate the possibility of confusion by zeroing out the base
of any freemap entry that has zero size. Because the freemap is not
intended to be a complete index of free space, a subsequent failure to
find any free space for a new xattr will trigger block compaction, which
regenerates the freemap.
It looks like this bug has been in the codebase for quite a long time.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_tcpmss: check remaining length before reading optlen
Quoting reporter:
In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads
op[i+1] directly without validating the remaining option length.
If the last byte of the option field is not EOL/NOP (0/1), the code attempts
to index op[i+1]. In the case where i + 1 == optlen, this causes an
out-of-bounds read, accessing memory past the optlen boundary
(either reading beyond the stack buffer _opt or the
following payload).
In the Linux kernel, the following vulnerability has been resolved:
net: usb: kaweth: remove TX queue manipulation in kaweth_set_rx_mode
kaweth_set_rx_mode(), the ndo_set_rx_mode callback, calls
netif_stop_queue() and netif_wake_queue(). These are TX queue flow
control functions unrelated to RX multicast configuration.
The premature netif_wake_queue() can re-enable TX while tx_urb is still
in-flight, leading to a double usb_submit_urb() on the same URB:
kaweth_start_xmit() {
netif_stop_queue();
usb_submit_urb(kaweth->tx_urb);
}
kaweth_set_rx_mode() {
netif_stop_queue();
netif_wake_queue(); // wakes TX queue before URB is done
}
kaweth_start_xmit() {
netif_stop_queue();
usb_submit_urb(kaweth->tx_urb); // URB submitted while active
}
This triggers the WARN in usb_submit_urb():
"URB submitted while active"
This is a similar class of bug fixed in rtl8150 by
- commit 958baf5eaee3 ("net: usb: Remove disruptive netif_wake_queue in rtl8150_set_multicast").
Also kaweth_set_rx_mode() is already functionally broken, the
real set_rx_mode action is performed by kaweth_async_set_rx_mode(),
which in turn is not a no-op only at ndo_open() time.
In the Linux kernel, the following vulnerability has been resolved:
media: ccs: Avoid possible division by zero
Calculating maximum M for scaler configuration involves dividing by
MIN_X_OUTPUT_SIZE limit register's value. Albeit the value is presumably
non-zero, the driver was missing the check it in fact was. Fix this.
In the Linux kernel, the following vulnerability has been resolved:
media: cx25821: Fix a resource leak in cx25821_dev_setup()
Add release_mem_region() if ioremap() fails to release the memory
region obtained by cx25821_get_resources().
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix reflink preserve cleanup issue
commit c06c303832ec ("ocfs2: fix xattr array entry __counted_by error")
doesn't handle all cases and the cleanup job for preserved xattr entries
still has bug:
- the 'last' pointer should be shifted by one unit after cleanup
an array entry.
- current code logic doesn't cleanup the first entry when xh_count is 1.
Note, commit c06c303832ec is also a bug fix for 0fe9b66c65f3.
In the Linux kernel, the following vulnerability has been resolved:
EFI/CPER: don't dump the entire memory region
The current logic at cper_print_fw_err() doesn't check if the
error record length is big enough to handle offset. On a bad firmware,
if the ofset is above the actual record, length -= offset will
underflow, making it dump the entire memory.
The end result can be:
- the logic taking a lot of time dumping large regions of memory;
- data disclosure due to the memory dumps;
- an OOPS, if it tries to dump an unmapped memory region.
Fix it by checking if the section length is too small before doing
a hex dump.
[ rjw: Subject tweaks ]
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: fix 22000 series SMEM parsing
If the firmware were to report three LMACs (which doesn't
exist in hardware) then using "fwrt->smem_cfg.lmac[2]" is
an overrun of the array. Reject such and use IWL_FW_CHECK
instead of WARN_ON in this function.
In the Linux kernel, the following vulnerability has been resolved:
media: tegra-video: Fix memory leak in __tegra_channel_try_format()
The state object allocated by __v4l2_subdev_state_alloc() must be freed
with __v4l2_subdev_state_free() when it is no longer needed.
In __tegra_channel_try_format(), two error paths return directly after
v4l2_subdev_call() fails, without freeing the allocated 'sd_state'
object. This violates the requirement and causes a memory leak.
Fix this by introducing a cleanup label and using goto statements in the
error paths to ensure that __v4l2_subdev_state_free() is always called
before the function returns.
In the Linux kernel, the following vulnerability has been resolved:
md/bitmap: fix GPF in write_page caused by resize race
A General Protection Fault occurs in write_page() during array resize:
RIP: 0010:write_page+0x22b/0x3c0 [md_mod]
This is a use-after-free race between bitmap_daemon_work() and
__bitmap_resize(). The daemon iterates over `bitmap->storage.filemap`
without locking, while the resize path frees that storage via
md_bitmap_file_unmap(). `quiesce()` does not stop the md thread,
allowing concurrent access to freed pages.
Fix by holding `mddev->bitmap_info.mutex` during the bitmap update.