A flaw was found in GLib. The D-Bus client-side implementation of the DBUS_COOKIE_SHA1 SASL authentication mechanism does not validate the cookie_context parameter received from the server. A malicious D-Bus server can supply a cookie_context containing path traversal sequences, causing the client to read an arbitrary file and exfiltrate sensitive data by verifying guessed file contents against a generated hash.
A flaw was found in GLib. A state confusion issue exists in g_dbus_node_info_new_for_xml() in the gio/gdbusintrospection.c file when processing malformed D-Bus introspection XML, specifically with a `node` element nested within other elements like `method`, `signal`, `property` or `arg`. This issue can cause an unsigned integer overflow and lead to an out-of-bounds read, resulting in a denial of service.
A flaw was found in sssd. When authenticating with a YubiKey, the SSSD PAM responder can crash due to a use-after-free vulnerability, where a memory pointer is incorrectly handled. A local attacker could exploit this flaw by manipulating smartcard or YubiKey contents, leading to a denial of service that disrupts authentication. This vulnerability also presents a potential for privilege escalation, although it is difficult to exploit.
A flaw was found in p11-kit. The RPC message attribute parsing functions p11_rpc_message_get_attribute() and p11_rpc_message_get_attribute_array_value() form a mutually-recursive call chain with no recursion depth limit when processing nested CKA_WRAP_TEMPLATE, CKA_UNWRAP_TEMPLATE, and CKA_DERIVE_TEMPLATE attributes. An unauthenticated attacker with local access to the p11-kit RPC Unix domain socket can send a specially crafted request with deeply nested template attributes, causing stack exhaustion and crashing the p11-kit server process and its dependent services.
A flaw was found in Yelp due to an overly permissive Content Security Policy (CSP) implementation provided by yelp-xsl. A malicious Flatpak application can open crafted help content through the OpenURI portal. By embedding an untrusted CSS stylesheet within a structured SVG document, attacker-controlled content can bypass Flatpak's intended sandbox isolation, allowing Yelp to evaluate local XML inclusions and disclose arbitrary user-readable host files through remote CSS resource requests. This may result in the unauthorized disclosure of sensitive information.
A flaw was found in spice-vdagent. A malicious or compromised SPICE host can trigger an integer overflow by sending a specially crafted message. This vulnerability can lead to a heap buffer overflow, causing the spice-vdagent daemon to crash and resulting in a Denial of Service (DoS) for the virtual machine. This issue requires the SPICE host to be untrusted or compromised for exploitation.
A path traversal vulnerability was found in spice-vdagent. This flaw allows a malicious or compromised SPICE host to write arbitrary files to any location on the guest operating system. This occurs because the filename provided by the SPICE host during file transfers is not properly sanitized before being used. An attacker could exploit this to write to sensitive locations with the privileges of the spice-vdagent process, typically the logged-in user. This issue requires the SPICE host to be untrusted or compromised for exploitation.
A flaw was found in the libblkid library of util-linux. During nested partition probing, the BSD, Minix, Solaris x86, and UnixWare partition probers cache a raw pointer to a parent partition entry in a dynamically allocated array. When subsequent partition additions cause the array to be reallocated, this pointer becomes stale, leading to a heap use-after-free read. An attacker who can present a crafted block device image (for example, via USB insertion or a loop-mounted disk image) can trigger this flaw without user interaction, as libblkid is invoked automatically by udev/udisks as root on block-device hot-plug events. This could lead to limited information disclosure or denial of service.
In the Linux kernel, the following vulnerability has been resolved:
mm/list_lru: drain before clearing xarray entry on reparent
memcg_reparent_list_lrus() clears the dying memcg's xarray entry with
xas_store(&xas, NULL) before reparenting its per-node lists into the
parent. This opens a window where a concurrent list_lru_del() arriving
for the dying memcg sees xa_load() == NULL, walks to the parent in
lock_list_lru_of_memcg(), takes the parent's per-node lock, and calls
list_del_init() on an item still physically linked on the dying memcg's
list.
If another in-flight thread holds the dying memcg's per-node lock at the
same moment (another list_lru_del, or a list_lru_walk_one running an
isolate callback), both threads modify ->next/->prev pointers on the same
physical list under different locks. Adjacent items can corrupt each
other's links.
Fix it by reversing the order: reparent each per-node list and mark the
child's list lru dead and then clear the xarray entry. Any concurrent
list_lru op that finds the still-set xarray entry either takes the dying
memcg's per-node lock (synchronizing with the drain) or sees LONG_MIN and
walks to the parent, where the items now live.
In the Linux kernel, the following vulnerability has been resolved:
drm/gem: Try to fix change_handle ioctl, attempt 4
[airlied: just added some comments on how to reenable]
On-list because the cat is out of the bag and we're clearly not good
enough to figure this out in private. The story thus far:
5e28b7b94408 ("drm: Set old handle to NULL before prime swap in
change_handle") tried to fix a race condition between the gem_close and
gem_change_handle ioctls, but got a few things wrong:
- There's a confusion with the local variable handle, which is actually
the new handle, and so the two-stage trick was actually applied to the
wrong idr slot. 7164d78559b0 ("drm/gem: fix race between
change_handle and handle_delete") tried to fix that by adding yet
another code block, but forgot to add the error handling. Which meant
we now have two paths, both kinda wrong.
- dc366607c41c ("drm: Replace old pointer to new idr") tried to apply
another fix, but inconsistently, again because of the handle confusion
- this would be the right fix (kinda, somewhat, it's a mess) if we'd
do the two-stage approach for the new handle. Except that wasn't the
intent of the original fix.
We also didn't have an igt merged for the original ioctl, which is a big
no-go. This was attempted to address off-list in the original bugfix,
and amd QA people claimed the bug was fixed now. Very clearly that's not
the case. Here's my attempt to sort this out:
- Rename the local variable to new_handle, the old aliasing with
args->handle is just too dangerously confusing.
- Merge the gem obj lookup with the two-stage idr_replace so that we
avoid getting ourselves confused there.
- This means we don't have a surplus temporary reference anymore, only
an inherited from the idr. A concurrent gem_close on the new_handle
could steal that. Fix that with the same two-stage approach
create_tail uses. This is a bit overkill as documented in the comment,
but I also don't trust my ability to understand this all correctly, so
go with the established pattern we have from other ioctls instead for
maximum paranoia.
- Adjust error paths. I've tried to make the error and success paths
common, because they are identical except for which handle is removed
and on which we call idr_replace to (re)install the object again. But
that made things messier to read, so I've left it at the more verbose
version, which unfortunately hides the symmetry in the entire code
flow a bit.
- While at it, also replace the 7 space indent with 1 tab.
And finally, because I flat out don't trust my abilities here at all
anymore:
- Disable the ioctl until we have the igt situation and everything else
sorted out on-list and with full consensus.
v2:
Sashiko noticed that I didn't handle the error path for idr_replace
correctly, it must be checked with IS_ERR_OR_NULL like in
gem_handle_delete. So yeah, definitely should just the existing paths
1:1 because this is endless amounts of tricky.
Also add the Fixes: line for the original ioctl, I forgot that too.