Security Vulnerabilities - CVEs Published In July 2024
In the Linux kernel, the following vulnerability has been resolved:
xhci: Handle TD clearing for multiple streams case
When multiple streams are in use, multiple TDs might be in flight when
an endpoint is stopped. We need to issue a Set TR Dequeue Pointer for
each, to ensure everything is reset properly and the caches cleared.
Change the logic so that any N>1 TDs found active for different streams
are deferred until after the first one is processed, calling
xhci_invalidate_cancelled_tds() again from xhci_handle_cmd_set_deq() to
queue another command until we are done with all of them. Also change
the error/"should never happen" paths to ensure we at least clear any
affected TDs, even if we can't issue a command to clear the hardware
cache, and complain loudly with an xhci_warn() if this ever happens.
This problem case dates back to commit e9df17eb1408 ("USB: xhci: Correct
assumptions about number of rings per endpoint.") early on in the XHCI
driver's life, when stream support was first added.
It was then identified but not fixed nor made into a warning in commit
674f8438c121 ("xhci: split handling halted endpoints into two steps"),
which added a FIXME comment for the problem case (without materially
changing the behavior as far as I can tell, though the new logic made
the problem more obvious).
Then later, in commit 94f339147fc3 ("xhci: Fix failure to give back some
cached cancelled URBs."), it was acknowledged again.
[Mathias: commit 94f339147fc3 ("xhci: Fix failure to give back some cached
cancelled URBs.") was a targeted regression fix to the previously mentioned
patch. Users reported issues with usb stuck after unmounting/disconnecting
UAS devices. This rolled back the TD clearing of multiple streams to its
original state.]
Apparently the commit author was aware of the problem (yet still chose
to submit it): It was still mentioned as a FIXME, an xhci_dbg() was
added to log the problem condition, and the remaining issue was mentioned
in the commit description. The choice of making the log type xhci_dbg()
for what is, at this point, a completely unhandled and known broken
condition is puzzling and unfortunate, as it guarantees that no actual
users would see the log in production, thereby making it nigh
undebuggable (indeed, even if you turn on DEBUG, the message doesn't
really hint at there being a problem at all).
It took me *months* of random xHC crashes to finally find a reliable
repro and be able to do a deep dive debug session, which could all have
been avoided had this unhandled, broken condition been actually reported
with a warning, as it should have been as a bug intentionally left in
unfixed (never mind that it shouldn't have been left in at all).
> Another fix to solve clearing the caches of all stream rings with
> cancelled TDs is needed, but not as urgent.
3 years after that statement and 14 years after the original bug was
introduced, I think it's finally time to fix it. And maybe next time
let's not leave bugs unfixed (that are actually worse than the original
bug), and let's actually get people to review kernel commits please.
Fixes xHC crashes and IOMMU faults with UAS devices when handling
errors/faults. Easiest repro is to use `hdparm` to mark an early sector
(e.g. 1024) on a disk as bad, then `cat /dev/sdX > /dev/null` in a loop.
At least in the case of JMicron controllers, the read errors end up
having to cancel two TDs (for two queued requests to different streams)
and the one that didn't get cleared properly ends up faulting the xHC
entirely when it tries to access DMA pages that have since been unmapped,
referred to by the stale TDs. This normally happens quickly (after two
or three loops). After this fix, I left the `cat` in a loop running
overnight and experienced no xHC failures, with all read errors
recovered properly. Repro'd and tested on an Apple M1 Mac Mini
(dwc3 host).
On systems without an IOMMU, this bug would instead silently corrupt
freed memory, making this a
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
net: ethtool: fix the error condition in ethtool_get_phy_stats_ethtool()
Clang static checker (scan-build) warning:
net/ethtool/ioctl.c:line 2233, column 2
Called function pointer is null (null dereference).
Return '-EOPNOTSUPP' when 'ops->get_ethtool_phy_stats' is NULL to fix
this typo error.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: mvm: check n_ssids before accessing the ssids
In some versions of cfg80211, the ssids poinet might be a valid one even
though n_ssids is 0. Accessing the pointer in this case will cuase an
out-of-bound access. Fix this by checking n_ssids first.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: validate HE operation element parsing
Validate that the HE operation element has the correct
length before parsing it.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
mptcp: ensure snd_una is properly initialized on connect
This is strictly related to commit fb7a0d334894 ("mptcp: ensure snd_nxt
is properly initialized on connect"). It turns out that syzkaller can
trigger the retransmit after fallback and before processing any other
incoming packet - so that snd_una is still left uninitialized.
Address the issue explicitly initializing snd_una together with snd_nxt
and write_seq.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
drm/exynos/vidi: fix memory leak in .get_modes()
The duplicated EDID is never freed. Fix it.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
iio: temperature: mlx90635: Fix ERR_PTR dereference in mlx90635_probe()
When devm_regmap_init_i2c() fails, regmap_ee could be error pointer,
instead of checking for IS_ERR(regmap_ee), regmap is checked which looks
like a copy paste error.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
HID: logitech-dj: Fix memory leak in logi_dj_recv_switch_to_dj_mode()
Fix a memory leak on logi_dj_recv_send_report() error path.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
bpf: Set run context for rawtp test_run callback
syzbot reported crash when rawtp program executed through the
test_run interface calls bpf_get_attach_cookie helper or any
other helper that touches task->bpf_ctx pointer.
Setting the run context (task->bpf_ctx pointer) for test_run
callback.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix a potential use-after-free in bpf_link_free()
After commit 1a80dbcb2dba, bpf_link can be freed by
link->ops->dealloc_deferred, but the code still tests and uses
link->ops->dealloc afterward, which leads to a use-after-free as
reported by syzbot. Actually, one of them should be sufficient, so
just call one of them instead of both. Also add a WARN_ON() in case
of any problematic implementation.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-12