CVE-2026-72048: ieee802154: ca8210: fix cas_ctl leak on spi_async failure

From: Greg Kroah-Hartman <[email protected]>

Description
===========

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

ieee802154: ca8210: fix cas_ctl leak on spi_async failure

ca8210_spi_transfer() allocates cas_ctl with kzalloc_obj(GFP_ATOMIC)
and relies entirely on the SPI completion callback
ca8210_spi_transfer_complete() to free it.

The spi_async() API only invokes the completion callback on successful
submission.  On failure it returns a negative error code without ever
queuing the callback, which leaves cas_ctl and its embedded spi_message
and spi_transfer orphaned.  Every kfree(cas_ctl) in the driver is
inside the completion callback, so there is no other reclamation path.

ca8210_spi_transfer() is called from ca8210_spi_exchange(), the
interrupt handler ca8210_interrupt_handler(), and from the retry path
inside the completion callback itself.  The exchange and interrupt
handler paths loop on -EBUSY, so under sustained SPI bus contention
every retry iteration leaks a fresh cas_ctl (~600 bytes per
occurrence).

Fix it by freeing cas_ctl on the spi_async() error path.  While here,
correct the misleading error string: the function calls spi_async(),
not spi_sync().

The Linux kernel CVE team has assigned CVE-2026-72048 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 4.12 with commit ded845a781a578dfb0b5b2c138e5a067aa3b1242 and fixed in 5.10.261 with commit 460c5cd51e4d7d15b317f178f42cfcb666c0fe91
	Issue introduced in 4.12 with commit ded845a781a578dfb0b5b2c138e5a067aa3b1242 and fixed in 5.15.212 with commit b07aea90dbc6e188c74c100af64b77b9482ffc65
	Issue introduced in 4.12 with commit ded845a781a578dfb0b5b2c138e5a067aa3b1242 and fixed in 6.1.178 with commit fe90605b651573d30be8293ff5be40e3d7023117
	Issue introduced in 4.12 with commit ded845a781a578dfb0b5b2c138e5a067aa3b1242 and fixed in 6.6.145 with commit b9071dc7889bef42590e04fbf3e56cc65e1e5e6e
	Issue introduced in 4.12 with commit ded845a781a578dfb0b5b2c138e5a067aa3b1242 and fixed in 6.12.97 with commit d4a397fe803c2d157f6ebb068b802ef75fbf109e
	Issue introduced in 4.12 with commit ded845a781a578dfb0b5b2c138e5a067aa3b1242 and fixed in 6.18.40 with commit cb5cca1d2a908ddd5e357971de0f2009617b8d6a
	Issue introduced in 4.12 with commit ded845a781a578dfb0b5b2c138e5a067aa3b1242 and fixed in 7.1.5 with commit 7e3630fbb6aabb844bbf35746dee0bf3894100c7
	Issue introduced in 4.12 with commit ded845a781a578dfb0b5b2c138e5a067aa3b1242 and fixed in 7.2-rc1 with commit e09390e439bd7cca30dd10893b1f64802961667a

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-72048
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ieee802154/ca8210.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/460c5cd51e4d7d15b317f178f42cfcb666c0fe91
	https://git.kernel.org/stable/c/b07aea90dbc6e188c74c100af64b77b9482ffc65
	https://git.kernel.org/stable/c/fe90605b651573d30be8293ff5be40e3d7023117
	https://git.kernel.org/stable/c/b9071dc7889bef42590e04fbf3e56cc65e1e5e6e
	https://git.kernel.org/stable/c/d4a397fe803c2d157f6ebb068b802ef75fbf109e
	https://git.kernel.org/stable/c/cb5cca1d2a908ddd5e357971de0f2009617b8d6a
	https://git.kernel.org/stable/c/7e3630fbb6aabb844bbf35746dee0bf3894100c7
	https://git.kernel.org/stable/c/e09390e439bd7cca30dd10893b1f64802961667a