CVE-2023-54036

published 2025-12-24

CVE-2023-54036: In the Linux kernel, the following vulnerability has been resolved: wifi: rtl8xxxu: Fix memory leaks with RTL8723BU, RTL8192EU The wifi + bluetooth combo chip…

Priority P4 19 medium 5.5

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

wifi: rtl8xxxu: Fix memory leaks with RTL8723BU, RTL8192EU

The wifi + bluetooth combo chip RTL8723BU can leak memory (especially?)
when it's connected to a bluetooth audio device. The busy bluetooth
traffic generates lots of C2H (card to host) messages, which are not
freed correctly.

To fix this, move the dev_kfree_skb() call in rtl8xxxu_c2hcmd_callback()
inside the loop where skb_dequeue() is called.

The RTL8192EU leaks memory because the C2H messages are added to the
queue and left there forever. (This was fine in the past because it
probably wasn't sending any C2H messages until commit e542e66b7c2e
("wifi: rtl8xxxu: gen2: Turn on the rate control"). Since that commit
it sends a C2H message when the TX rate changes.)

To fix this, delete the check for rf_paths > 1 and the goto. Let the
function process the C2H messages from RTL8192EU like the ones from
the other chips.

Theoretically the RTL8188FU could also leak like RTL8723BU, but it
most likely doesn't send C2H messages frequently enough.

This change was tested with RTL8723BU by Erhard F. I tested it with
RTL8188FU and RTL8192EU.

Affected

15 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 6.1.20-1 (bookworm)	linux 6.1.20-1 (bookworm)
linux	linux	—	—
linux	linux	>= e542e66b7c2ee2adeefdbb7f259f2f60cadf2819 < 430f9f9bec53a75f9ccc53e156a66f13fc098b83	430f9f9bec53a75f9ccc53e156a66f13fc098b83
linux	linux	>= e542e66b7c2ee2adeefdbb7f259f2f60cadf2819 < 35fb0e275af1aa1ca0a9784417e90f988aaf8e78	35fb0e275af1aa1ca0a9784417e90f988aaf8e78
linux	linux	>= e542e66b7c2ee2adeefdbb7f259f2f60cadf2819 < 93c3f34ec02fc81188d328287d4fddd498ccddea	93c3f34ec02fc81188d328287d4fddd498ccddea
linux	linux	>= e542e66b7c2ee2adeefdbb7f259f2f60cadf2819 < f39a86b4efd270947ee252cc32a30b0aef492d65	f39a86b4efd270947ee252cc32a30b0aef492d65
linux	linux	>= e542e66b7c2ee2adeefdbb7f259f2f60cadf2819 < b39f662ce1648db0b9de32e6a849b098480793cb	b39f662ce1648db0b9de32e6a849b098480793cb
linux	linux_kernel	>= 0 < 5.10.178-1	5.10.178-1
linux	linux_kernel	>= 0 < 6.1.20-1	6.1.20-1
linux	linux_kernel	>= 0 < 6.1.20-1	6.1.20-1
linux	linux_kernel	>= 0 < 6.1.20-1	6.1.20-1
linux	linux_kernel	>= 5.11.0 < 5.15.99	5.15.99
linux	linux_kernel	>= 5.16.0 < 6.1.16	6.1.16
linux	linux_kernel	>= 5.5.0 < 5.10.173	5.10.173
linux	linux_kernel	>= 6.2.0 < 6.2.3	6.2.3

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