In the Linux kernel, the following vulnerability has been resolved:
minix: Add required sanity checking to minix_check_superblock()
The fs/minix implementation of the minix filesystem does not currently
support any other value for s_log_zone_size than 0. This is also the
only value supported in util-linux; see mkfs.minix.c line 511. In
addition, this patch adds some sanity checking for the other minix
superblock fields, and moves the minix_blocks_needed() checks for the
zmap and imap also to minix_check_super_block().
This also closes a related syzbot bug report.
In the Linux kernel, the following vulnerability has been resolved:
atm: fore200e: fix use-after-free in tasklets during device removal
When the PCA-200E or SBA-200E adapter is being detached, the fore200e
is deallocated. However, the tx_tasklet or rx_tasklet may still be running
or pending, leading to use-after-free bug when the already freed fore200e
is accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet().
One of the race conditions can occur as follows:
CPU 0 (cleanup) | CPU 1 (tasklet)
fore200e_pca_remove_one() | fore200e_interrupt()
fore200e_shutdown() | tasklet_schedule()
kfree(fore200e) | fore200e_tx_tasklet()
| fore200e-> // UAF
Fix this by ensuring tx_tasklet or rx_tasklet is properly canceled before
the fore200e is released. Add tasklet_kill() in fore200e_shutdown() to
synchronize with any pending or running tasklets. Moreover, since
fore200e_reset() could prevent further interrupts or data transfers,
the tasklet_kill() should be placed after fore200e_reset() to prevent
the tasklet from being rescheduled in fore200e_interrupt(). Finally,
it only needs to do tasklet_kill() when the fore200e state is greater
than or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized
in earlier states. In a word, the tasklet_kill() should be placed in
the FORE200E_STATE_IRQ branch within the switch...case structure.
This bug was identified through static analysis.
In the Linux kernel, the following vulnerability has been resolved:
tcp: fix potential race in tcp_v6_syn_recv_sock()
Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock()
is done too late.
After tcp_v4_syn_recv_sock(), the child socket is already visible
from TCP ehash table and other cpus might use it.
Since newinet->pinet6 is still pointing to the listener ipv6_pinfo
bad things can happen as syzbot found.
Move the problematic code in tcp_v6_mapped_child_init()
and call this new helper from tcp_v4_syn_recv_sock() before
the ehash insertion.
This allows the removal of one tcp_sync_mss(), since
tcp_v4_syn_recv_sock() will call it with the correct
context.
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:
net: usb: pegasus: enable basic endpoint checking
pegasus_probe() fills URBs with hardcoded endpoint pipes without
verifying the endpoint descriptors:
- usb_rcvbulkpipe(dev, 1) for RX data
- usb_sndbulkpipe(dev, 2) for TX data
- usb_rcvintpipe(dev, 3) for status interrupts
A malformed USB device can present these endpoints with transfer types
that differ from what the driver assumes.
Add a pegasus_usb_ep enum for endpoint numbers, replacing magic
constants throughout. Add usb_check_bulk_endpoints() and
usb_check_int_endpoints() calls before any resource allocation to
verify endpoint types before use, rejecting devices with mismatched
descriptors at probe time, and avoid triggering assertion.
Similar fix to
- commit 90b7f2961798 ("net: usb: rtl8150: enable basic endpoint checking")
- commit 9e7021d2aeae ("net: usb: catc: enable basic endpoint checking")
In the Linux kernel, the following vulnerability has been resolved:
xfs: fix freemap adjustments when adding xattrs to leaf blocks
xfs/592 and xfs/794 both trip this assertion in the leaf block freemap
adjustment code after ~20 minutes of running on my test VMs:
ASSERT(ichdr->firstused >= ichdr->count * sizeof(xfs_attr_leaf_entry_t)
+ xfs_attr3_leaf_hdr_size(leaf));
Upon enabling quite a lot more debugging code, I narrowed this down to
fsstress trying to set a local extended attribute with namelen=3 and
valuelen=71. This results in an entry size of 80 bytes.
At the start of xfs_attr3_leaf_add_work, the freemap looks like this:
i 0 base 448 size 0 rhs 448 count 46
i 1 base 388 size 132 rhs 448 count 46
i 2 base 2120 size 4 rhs 448 count 46
firstused = 520
where "rhs" is the first byte past the end of the leaf entry array.
This is inconsistent -- the entries array ends at byte 448, but
freemap[1] says there's free space starting at byte 388!
By the end of the function, the freemap is in worse shape:
i 0 base 456 size 0 rhs 456 count 47
i 1 base 388 size 52 rhs 456 count 47
i 2 base 2120 size 4 rhs 456 count 47
firstused = 440
Important note: 388 is not aligned with the entries array element size
of 8 bytes.
Based on the incorrect freemap, the name area starts at byte 440, which
is below the end of the entries array! That's why the assertion
triggers and the filesystem shuts down.
How did we end up here? First, recall from the previous patch that the
freemap array in an xattr leaf block is not intended to be a
comprehensive map of all free space in the leaf block. In other words,
it's perfectly legal to have a leaf block with:
* 376 bytes in use by the entries array
* freemap[0] has [base = 376, size = 8]
* freemap[1] has [base = 388, size = 1500]
* the space between 376 and 388 is free, but the freemap stopped
tracking that some time ago
If we add one xattr, the entries array grows to 384 bytes, and
freemap[0] becomes [base = 384, size = 0]. So far, so good. But if we
add a second xattr, the entries array grows to 392 bytes, and freemap[0]
gets pushed up to [base = 392, size = 0]. This is bad, because
freemap[1] hasn't been updated, and now the entries array and the free
space claim the same space.
The fix here is to adjust all freemap entries so that none of them
collide with the entries array. Note that this fix relies on commit
2a2b5932db6758 ("xfs: fix attr leaf header freemap.size underflow") and
the previous patch that resets zero length freemap entries to have
base = 0.
In the Linux kernel, the following vulnerability has been resolved:
HID: hid-pl: handle probe errors
Errors in init must be reported back or we'll
follow a NULL pointer the first time FF is used.
In the Linux kernel, the following vulnerability has been resolved:
xfrm6: fix uninitialized saddr in xfrm6_get_saddr()
xfrm6_get_saddr() does not check the return value of
ipv6_dev_get_saddr(). When ipv6_dev_get_saddr() fails to find a suitable
source address (returns -EADDRNOTAVAIL), saddr->in6 is left
uninitialized, but xfrm6_get_saddr() still returns 0 (success).
This causes the caller xfrm_tmpl_resolve_one() to use the uninitialized
address in xfrm_state_find(), triggering KMSAN warning:
=====================================================
BUG: KMSAN: uninit-value in xfrm_state_find+0x2424/0xa940
xfrm_state_find+0x2424/0xa940
xfrm_resolve_and_create_bundle+0x906/0x5a20
xfrm_lookup_with_ifid+0xcc0/0x3770
xfrm_lookup_route+0x63/0x2b0
ip_route_output_flow+0x1ce/0x270
udp_sendmsg+0x2ce1/0x3400
inet_sendmsg+0x1ef/0x2a0
__sock_sendmsg+0x278/0x3d0
__sys_sendto+0x593/0x720
__x64_sys_sendto+0x130/0x200
x64_sys_call+0x332b/0x3e70
do_syscall_64+0xd3/0xf80
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Local variable tmp.i.i created at:
xfrm_resolve_and_create_bundle+0x3e3/0x5a20
xfrm_lookup_with_ifid+0xcc0/0x3770
=====================================================
Fix by checking the return value of ipv6_dev_get_saddr() and propagating
the error.