Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: caiaq: fix usb_dev refcount leak on probe failure create_card() takes a reference on the USB device with usb_get_dev() and stores the matching usb_put_dev() in card_free(), which is installed as the snd_card's ->private_free destructor. However, ->private_free is only assigned near the end of init_card(), after several failure points (usb_set_interface(), EP type checks, usb_submit_urb(), the EP1_CMD_GET_DEVICE_INFO exchange, and its timeout). When any of those fail, init_card() returns an error to snd_probe(), which calls snd_card_free(card). Because ->private_free is still NULL, card_free() never runs, the usb_get_dev() reference is not dropped, and the struct usb_device leaks along with its descriptor allocations and device_private. syzbot reproduces this with a malformed UAC3 device whose only valid altsetting is 0; init_card()'s usb_set_interface(usb_dev, 0, 1) call fails with -EIO and triggers the leak. Move the ->private_free assignment into create_card(), immediately after usb_get_dev(), so that every error path reaching snd_card_free() balances the reference. card_free()'s callees (snd_usb_caiaq_input_free, free_urbs, kfree) already tolerate the partially-initialized state because the chip private area is zero-initialized by snd_card_new().
Product status
493b3a682ededc804555755f5d2193201339612d (git) before c874db8a1d2f9f08161470d00cfe8db2f5cca2cc
dbcf7588e8dea017ddb3f18ec2766f7d2e5f2a0e (git) before 6fa8dff64fb6c401ced40a05797b327659317498
ac7345f68cda6989016d85d63f7b244c064aa8f6 (git) before a8d907acc3e5a078c2e5637ff60c30c6d2ddc23a
f6634af5de728a46792f674a66d7843570cb68f7 (git) before 50c6a1f05973f56d23280c9d7645a7a5734e0907
1d9be95aee6c6246a21752e60c9519902649f482 (git) before da3b8fd6a202d94fef11a443abc9171c52426a1c
6473ed16df1fe88051140611b3eb9a49be7f429e (git) before 6153878c5255bb69b7d0868105ca078ef13cbcf8
59b622a043cffc58b7638cd85ae6c30a0904f8e6 (git) before 21ca595aafa40d3ac70eab1f4cb62cc00ca21657
80bb50e2d459213cccff3111d5ef98ed4238c0d5 (git) before 7a5f1cd22d47f8ca4b760b6334378ae42c1bd24b
6.6.136 (semver) before 6.6.140
6.12.84 (semver) before 6.12.86
6.18.25 (semver) before 6.18.27
7.0.2 (semver) before 7.0.4
7.1-rc1
Any version before 7.1-rc1
6.6.140 (semver)
6.12.86 (semver)
6.18.27 (semver)
7.0.4 (semver)
7.1-rc2 (original_commit_for_fix)
References
git.kernel.org/...c/c874db8a1d2f9f08161470d00cfe8db2f5cca2cc
git.kernel.org/...c/6fa8dff64fb6c401ced40a05797b327659317498
git.kernel.org/...c/a8d907acc3e5a078c2e5637ff60c30c6d2ddc23a
git.kernel.org/...c/50c6a1f05973f56d23280c9d7645a7a5734e0907
git.kernel.org/...c/da3b8fd6a202d94fef11a443abc9171c52426a1c
git.kernel.org/...c/6153878c5255bb69b7d0868105ca078ef13cbcf8
git.kernel.org/...c/21ca595aafa40d3ac70eab1f4cb62cc00ca21657
git.kernel.org/...c/7a5f1cd22d47f8ca4b760b6334378ae42c1bd24b