Archivos anuales: 2024

In the Linux kernel, the following vulnerability has been resolved:

netfs/fscache: Add a memory barrier for FSCACHE_VOLUME_CREATING

In fscache_create_volume(), there is a missing memory barrier between the
bit-clearing operation and the wake-up operation. This may cause a
situation where, after a wake-up, the bit-clearing operation hasn't been
detected yet, leading to an indefinite wait. The triggering process is as
follows:

[cookie1] [cookie2] [volume_work]
fscache_perform_lookup
fscache_create_volume
fscache_perform_lookup
fscache_create_volume
fscache_create_volume_work
cachefiles_acquire_volume
clear_and_wake_up_bit
test_and_set_bit
test_and_set_bit
goto maybe_wait
goto no_wait

In the above process, cookie1 and cookie2 has the same volume. When cookie1
enters the -no_wait- process, it will clear the bit and wake up the waiting
process. If a barrier is missing, it may cause cookie2 to remain in the
-wait- process indefinitely.

In commit 3288666c7256 ("fscache: Use clear_and_wake_up_bit() in
fscache_create_volume_work()"), barriers were added to similar operations
in fscache_create_volume_work(), but fscache_create_volume() was missed.

By combining the clear and wake operations into clear_and_wake_up_bit() to
fix this issue.

A vulnerability, which was classified as problematic, was found in PHPGurukul Maid Hiring Management System 1.0. Affected is an unknown function of the file /admin/contactus.php of the component Contact Us Page. The manipulation of the argument page title leads to cross site scripting. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.

In the Linux kernel, the following vulnerability has been resolved:

net: mscc: ocelot: fix incorrect IFH SRC_PORT field in ocelot_ifh_set_basic()

Packets injected by the CPU should have a SRC_PORT field equal to the
CPU port module index in the Analyzer block (ocelot->num_phys_ports).

The blamed commit copied the ocelot_ifh_set_basic() call incorrectly
from ocelot_xmit_common() in net/dsa/tag_ocelot.c. Instead of calling
with "x", it calls with BIT_ULL(x), but the field is not a port mask,
but rather a single port index.

[ side note: this is the technical debt of code duplication 🙁 ]

The error used to be silent and doesn't appear to have other
user-visible manifestations, but with new changes in the packing
library, it now fails loudly as follows:

————[ cut here ]————
Cannot store 0x40 inside bits 46-43 – will truncate
sja1105 spi2.0: xmit timed out
WARNING: CPU: 1 PID: 102 at lib/packing.c:98 __pack+0x90/0x198
sja1105 spi2.0: timed out polling for tstamp
CPU: 1 UID: 0 PID: 102 Comm: felix_xmit
Tainted: G W N 6.13.0-rc1-00372-gf706b85d972d-dirty #2605
Call trace:
__pack+0x90/0x198 (P)
__pack+0x90/0x198 (L)
packing+0x78/0x98
ocelot_ifh_set_basic+0x260/0x368
ocelot_port_inject_frame+0xa8/0x250
felix_port_deferred_xmit+0x14c/0x258
kthread_worker_fn+0x134/0x350
kthread+0x114/0x138

The code path pertains to the ocelot switchdev driver and to the felix
secondary DSA tag protocol, ocelot-8021q. Here seen with ocelot-8021q.

The messenger (packing) is not really to blame, so fix the original
commit instead.

In the Linux kernel, the following vulnerability has been resolved:

netdevsim: prevent bad user input in nsim_dev_health_break_write()

If either a zero count or a large one is provided, kernel can crash.

In the Linux kernel, the following vulnerability has been resolved:

ionic: Fix netdev notifier unregister on failure

If register_netdev() fails, then the driver leaks the netdev notifier.
Fix this by calling ionic_lif_unregister() on register_netdev()
failure. This will also call ionic_lif_unregister_phc() if it has
already been registered.

In the Linux kernel, the following vulnerability has been resolved:

ionic: no double destroy workqueue

There are some FW error handling paths that can cause us to
try to destroy the workqueue more than once, so let's be sure
we're checking for that.

The case where this popped up was in an AER event where the
handlers got called in such a way that ionic_reset_prepare()
and thus ionic_dev_teardown() got called twice in a row.
The second time through the workqueue was already destroyed,
and destroy_workqueue() choked on the bad wq pointer.

We didn't hit this in AER handler testing before because at
that time we weren't using a private workqueue. Later we
replaced the use of the system workqueue with our own private
workqueue but hadn't rerun the AER handler testing since then.

In the Linux kernel, the following vulnerability has been resolved:

net: netdevsim: fix nsim_pp_hold_write()

nsim_pp_hold_write() has two problems:

1) It may return with rtnl held, as found by syzbot.

2) Its return value does not propagate an error if any.

In the Linux kernel, the following vulnerability has been resolved:

udmabuf: fix memory leak on last export_udmabuf() error path

In export_udmabuf(), if dma_buf_fd() fails because the FD table is full, a
dma_buf owning the udmabuf has already been created; but the error handling
in udmabuf_create() will tear down the udmabuf without doing anything about
the containing dma_buf.

This leaves a dma_buf in memory that contains a dangling pointer; though
that doesn't seem to lead to anything bad except a memory leak.

Fix it by moving the dma_buf_fd() call out of export_udmabuf() so that we
can give it different error handling.

Note that the shape of this code changed a lot in commit 5e72b2b41a21
("udmabuf: convert udmabuf driver to use folios"); but the memory leak
seems to have existed since the introduction of udmabuf.

In the Linux kernel, the following vulnerability has been resolved:

drm/panel: himax-hx83102: Add a check to prevent NULL pointer dereference

drm_mode_duplicate() could return NULL due to lack of memory,
which will then call NULL pointer dereference. Add a check to
prevent it.

In the Linux kernel, the following vulnerability has been resolved:

net: stmmac: fix TSO DMA API usage causing oops

Commit 66600fac7a98 ("net: stmmac: TSO: Fix unbalanced DMA map/unmap
for non-paged SKB data") moved the assignment of tx_skbuff_dma[]'s
members to be later in stmmac_tso_xmit().

The buf (dma cookie) and len stored in this structure are passed to
dma_unmap_single() by stmmac_tx_clean(). The DMA API requires that
the dma cookie passed to dma_unmap_single() is the same as the value
returned from dma_map_single(). However, by moving the assignment
later, this is not the case when priv->dma_cap.addr64 > 32 as "des"
is offset by proto_hdr_len.

This causes problems such as:

dwc-eth-dwmac 2490000.ethernet eth0: Tx DMA map failed

and with DMA_API_DEBUG enabled:

DMA-API: dwc-eth-dwmac 2490000.ethernet: device driver tries to +free DMA memory it has not allocated [device address=0x000000ffffcf65c0] [size=66 bytes]

Fix this by maintaining "des" as the original DMA cookie, and use
tso_des to pass the offset DMA cookie to stmmac_tso_allocator().

Full details of the crashes can be found at:
https://lore.kernel.org/all/d8112193-0386-4e14-b516-37c2d838171a@nvidia.com/
https://lore.kernel.org/all/klkzp5yn5kq5efgtrow6wbvnc46bcqfxs65nz3qy77ujr5turc@bwwhelz2l4dw/