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: 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).
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Increase array size of dummy_boolean
[WHY]
dml2_core_shared_mode_support and dml_core_mode_support access the third
element of dummy_boolean, i.e. hw_debug5 = &s->dummy_boolean[2], when
dummy_boolean has size of 2. Any assignment to hw_debug5 causes an
OVERRUN.
[HOW]
Increase dummy_boolean's array size to 3.
This fixes 2 OVERRUN issues reported by Coverity.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Deallocate DML memory if allocation fails
[Why]
When DC state create DML memory allocation fails, memory is not
deallocated subsequently, resulting in uninitialized structure
that is not NULL.
[How]
Deallocate memory if DML memory allocation fails.
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Limit the number of concurrent async COPY operations
Nothing appears to limit the number of concurrent async COPY
operations that clients can start. In addition, AFAICT each async
COPY can copy an unlimited number of 4MB chunks, so can run for a
long time. Thus IMO async COPY can become a DoS vector.
Add a restriction mechanism that bounds the number of concurrent
background COPY operations. Start simple and try to be fair -- this
patch implements a per-namespace limit.
An async COPY request that occurs while this limit is exceeded gets
NFS4ERR_DELAY. The requesting client can choose to send the request
again after a delay or fall back to a traditional read/write style
copy.
If there is need to make the mechanism more sophisticated, we can
visit that in future patches.
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix timer use-after-free on failed mount
Syzbot has found an ODEBUG bug in ext4_fill_super
The del_timer_sync function cancels the s_err_report timer,
which reminds about filesystem errors daily. We should
guarantee the timer is no longer active before kfree(sbi).
When filesystem mounting fails, the flow goes to failed_mount3,
where an error occurs when ext4_stop_mmpd is called, causing
a read I/O failure. This triggers the ext4_handle_error function
that ultimately re-arms the timer,
leaving the s_err_report timer active before kfree(sbi) is called.
Fix the issue by canceling the s_err_report timer after calling ext4_stop_mmpd.
In the Linux kernel, the following vulnerability has been resolved:
ext4: filesystems without casefold feature cannot be mounted with siphash
When mounting the ext4 filesystem, if the default hash version is set to
DX_HASH_SIPHASH but the casefold feature is not set, exit the mounting.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Implement bounds check for stream encoder creation in DCN401
'stream_enc_regs' array is an array of dcn10_stream_enc_registers
structures. The array is initialized with four elements, corresponding
to the four calls to stream_enc_regs() in the array initializer. This
means that valid indices for this array are 0, 1, 2, and 3.
The error message 'stream_enc_regs' 4 <= 5 below, is indicating that
there is an attempt to access this array with an index of 5, which is
out of bounds. This could lead to undefined behavior
Here, eng_id is used as an index to access the stream_enc_regs array. If
eng_id is 5, this would result in an out-of-bounds access on the
stream_enc_regs array.
Thus fixing Buffer overflow error in dcn401_stream_encoder_create
Found by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn401/dcn401_resource.c:1209 dcn401_stream_encoder_create() error: buffer overflow 'stream_enc_regs' 4 <= 5
In the Linux kernel, the following vulnerability has been resolved:
net/ncsi: Disable the ncsi work before freeing the associated structure
The work function can run after the ncsi device is freed, resulting
in use-after-free bugs or kernel panic.