In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ALSA: usb-audio: Clamp implicit feedback packet count to URB capacity<\/p>\n
data_ep_set_params() allocates each data URB for exactly u->packets
\nisochronous frames, so urb->iso_frame_desc[] has u->packets slots and
\nctx->packets is the driver’s only record of that limit. For an implicit
\nfeedback sink, snd_usb_queue_pending_output_urbs() overwrites it with the
\nsync source’s packet count, which is calculated independently from the
\ncapture endpoint’s parameters. When that count is larger,
\nprepare_playback_urb() and prepare_silent_urb() can write
\niso_frame_desc[] past the allocation; their existing bounds limit payload
\nbytes, not the descriptor index.<\/p>\n
The reproducer uses a high-speed UAC2 device declaring bInterval 1 for
\nimplicit feedback capture (8 packets) and bInterval 4 for playback
\n(1 packet). On the first capture completion after the stream starts, it
\naccesses seven descriptors spanning 112 bytes beyond the one-packet URB:<\/p>\n
BUG: KASAN: slab-out-of-bounds in prepare_playback_urb (sound\/usb\/pcm.c:1560)
\n Write of size 4 at addr ffff88801e696ad0 by task vhci_rx\/178
\n prepare_playback_urb (sound\/usb\/pcm.c:1560)
\n prepare_outbound_urb (sound\/usb\/endpoint.c:340)
\n snd_usb_queue_pending_output_urbs (sound\/usb\/endpoint.c:501)
\n snd_complete_urb (sound\/usb\/endpoint.c:1834)
\n __usb_hcd_giveback_urb (drivers\/usb\/core\/hcd.c:1657)
\n usb_hcd_giveback_urb (drivers\/usb\/core\/hcd.c:1741)
\n vhci_rx_loop (drivers\/usb\/usbip\/vhci_rx.c:107)
\n kthread (kernel\/kthread.c:436)
\n The buggy address belongs to the object at ffff88801e696a00
\n which belongs to the cache kmalloc-256 of size 256
\n The buggy address is located 0 bytes to the right of
\n allocated 208-byte region [ffff88801e696a00, ffff88801e696ad0)<\/p>\n
Record the allocated packet count per endpoint and clamp both the adopted
\ncount and the packet-size copy to it. Fold the Format Type II delimiter
\ninto urb_packs before the allocation loop so the recorded limit matches
\nevery URB.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ALSA: usb-audio: Clamp implicit feedback packet count to URB capacity<\/p>\n
data_ep_set_params() allocates each data URB for exactly u-><\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-33334","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/33334","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=33334"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=33334"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=33334"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}