In the Linux kernel, the following vulnerability has been resolved:
bpftool: Fix undefined behavior in qsort(NULL, 0, ...)
When netfilter has no entry to display, qsort is called with
qsort(NULL, 0, ...). This results in undefined behavior, as UBSan
reports:
net.c:827:2: runtime error: null pointer passed as argument 1, which is declared to never be null
Although the C standard does not explicitly state whether calling qsort
with a NULL pointer when the size is 0 constitutes undefined behavior,
Section 7.1.4 of the C standard (Use of library functions) mentions:
"Each of the following statements applies unless explicitly stated
otherwise in the detailed descriptions that follow: If an argument to a
function has an invalid value (such as a value outside the domain of
the function, or a pointer outside the address space of the program, or
a null pointer, or a pointer to non-modifiable storage when the
corresponding parameter is not const-qualified) or a type (after
promotion) not expected by a function with variable number of
arguments, the behavior is undefined."
To avoid this, add an early return when nf_link_info is NULL to prevent
calling qsort with a NULL pointer.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: add refcnt to ksmbd_conn struct
When sending an oplock break request, opinfo->conn is used,
But freed ->conn can be used on multichannel.
This patch add a reference count to the ksmbd_conn struct
so that it can be freed when it is no longer used.
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/hdcp: Check GSC structure validity
Sometimes xe_gsc is not initialized when checked at HDCP capability
check. Add gsc structure check to avoid null pointer error.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: amdkfd_free_gtt_mem clear the correct pointer
Pass pointer reference to amdgpu_bo_unref to clear the correct pointer,
otherwise amdgpu_bo_unref clear the local variable, the original pointer
not set to NULL, this could cause use-after-free bug.
In the Linux kernel, the following vulnerability has been resolved:
drm/stm: Avoid use-after-free issues with crtc and plane
ltdc_load() calls functions drm_crtc_init_with_planes(),
drm_universal_plane_init() and drm_encoder_init(). These functions
should not be called with parameters allocated with devm_kzalloc()
to avoid use-after-free issues [1].
Use allocations managed by the DRM framework.
Found by Linux Verification Center (linuxtesting.org).
[1]
https://lore.kernel.org/lkml/u366i76e3qhh3ra5oxrtngjtm2u5lterkekcz6y2jkndhuxzli@diujon4h7qwb/
In the Linux kernel, the following vulnerability has been resolved:
block: fix integer overflow in BLKSECDISCARD
I independently rediscovered
commit 22d24a544b0d49bbcbd61c8c0eaf77d3c9297155
block: fix overflow in blk_ioctl_discard()
but for secure erase.
Same problem:
uint64_t r[2] = {512, 18446744073709551104ULL};
ioctl(fd, BLKSECDISCARD, r);
will enter near infinite loop inside blkdev_issue_secure_erase():
a.out: attempt to access beyond end of device
loop0: rw=5, sector=3399043073, nr_sectors = 1024 limit=2048
bio_check_eod: 3286214 callbacks suppressed
In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix buffer overflow when parsing NFS reparse points
ReparseDataLength is sum of the InodeType size and DataBuffer size.
So to get DataBuffer size it is needed to subtract InodeType's size from
ReparseDataLength.
Function cifs_strndup_from_utf16() is currentlly accessing buf->DataBuffer
at position after the end of the buffer because it does not subtract
InodeType size from the length. Fix this problem and correctly subtract
variable len.
Member InodeType is present only when reparse buffer is large enough. Check
for ReparseDataLength before accessing InodeType to prevent another invalid
memory access.
Major and minor rdev values are present also only when reparse buffer is
large enough. Check for reparse buffer size before calling reparse_mkdev().
In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: lantiq_etop: fix memory disclosure
When applying padding, the buffer is not zeroed, which results in memory
disclosure. The mentioned data is observed on the wire. This patch uses
skb_put_padto() to pad Ethernet frames properly. The mentioned function
zeroes the expanded buffer.
In case the packet cannot be padded it is silently dropped. Statistics
are also not incremented. This driver does not support statistics in the
old 32-bit format or the new 64-bit format. These will be added in the
future. In its current form, the patch should be easily backported to
stable versions.
Ethernet MACs on Amazon-SE and Danube cannot do padding of the packets
in hardware, so software padding must be applied.
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: improve shutdown sequence
Alexander Sverdlin presents 2 problems during shutdown with the
lan9303 driver. One is specific to lan9303 and the other just happens
to reproduce there.
The first problem is that lan9303 is unique among DSA drivers in that it
calls dev_get_drvdata() at "arbitrary runtime" (not probe, not shutdown,
not remove):
phy_state_machine()
-> ...
-> dsa_user_phy_read()
-> ds->ops->phy_read()
-> lan9303_phy_read()
-> chip->ops->phy_read()
-> lan9303_mdio_phy_read()
-> dev_get_drvdata()
But we never stop the phy_state_machine(), so it may continue to run
after dsa_switch_shutdown(). Our common pattern in all DSA drivers is
to set drvdata to NULL to suppress the remove() method that may come
afterwards. But in this case it will result in an NPD.
The second problem is that the way in which we set
dp->conduit->dsa_ptr = NULL; is concurrent with receive packet
processing. dsa_switch_rcv() checks once whether dev->dsa_ptr is NULL,
but afterwards, rather than continuing to use that non-NULL value,
dev->dsa_ptr is dereferenced again and again without NULL checks:
dsa_conduit_find_user() and many other places. In between dereferences,
there is no locking to ensure that what was valid once continues to be
valid.
Both problems have the common aspect that closing the conduit interface
solves them.
In the first case, dev_close(conduit) triggers the NETDEV_GOING_DOWN
event in dsa_user_netdevice_event() which closes user ports as well.
dsa_port_disable_rt() calls phylink_stop(), which synchronously stops
the phylink state machine, and ds->ops->phy_read() will thus no longer
call into the driver after this point.
In the second case, dev_close(conduit) should do this, as per
Documentation/networking/driver.rst:
| Quiescence
| ----------
|
| After the ndo_stop routine has been called, the hardware must
| not receive or transmit any data. All in flight packets must
| be aborted. If necessary, poll or wait for completion of
| any reset commands.
So it should be sufficient to ensure that later, when we zeroize
conduit->dsa_ptr, there will be no concurrent dsa_switch_rcv() call
on this conduit.
The addition of the netif_device_detach() function is to ensure that
ioctls, rtnetlinks and ethtool requests on the user ports no longer
propagate down to the driver - we're no longer prepared to handle them.
The race condition actually did not exist when commit 0650bf52b31f
("net: dsa: be compatible with masters which unregister on shutdown")
first introduced dsa_switch_shutdown(). It was created later, when we
stopped unregistering the user interfaces from a bad spot, and we just
replaced that sequence with a racy zeroization of conduit->dsa_ptr
(one which doesn't ensure that the interfaces aren't up).