Description
In the Linux kernel, the following vulnerability has been resolved: media: imon: make send_packet() more robust syzbot is reporting that imon has three problems which result in hung tasks due to forever holding device lock [1]. First problem is that when usb_rx_callback_intf0() once got -EPROTO error after ictx->dev_present_intf0 became true, usb_rx_callback_intf0() resubmits urb after printk(), and resubmitted urb causes usb_rx_callback_intf0() to again get -EPROTO error. This results in printk() flooding (RCU stalls). Alan Stern commented [2] that In theory it's okay to resubmit _if_ the driver has a robust error-recovery scheme (such as giving up after some fixed limit on the number of errors or after some fixed time has elapsed, perhaps with a time delay to prevent a flood of errors). Most drivers don't bother to do this; they simply give up right away. This makes them more vulnerable to short-term noise interference during USB transfers, but in reality such interference is quite rare. There's nothing really wrong with giving up right away. but imon has a poor error-recovery scheme which just retries forever; this behavior should be fixed. Since I'm not sure whether it is safe for imon users to give up upon any error code, this patch takes care of only union of error codes chosen from modules in drivers/media/rc/ directory which handle -EPROTO error (i.e. ir_toy, mceusb and igorplugusb). Second problem is that when usb_rx_callback_intf0() once got -EPROTO error before ictx->dev_present_intf0 becomes true, usb_rx_callback_intf0() always resubmits urb due to commit 8791d63af0cf ("[media] imon: don't wedge hardware after early callbacks"). Move the ictx->dev_present_intf0 test introduced by commit 6f6b90c9231a ("[media] imon: don't parse scancodes until intf configured") to immediately before imon_incoming_packet(), or the first problem explained above happens without printk() flooding (i.e. hung task). Third problem is that when usb_rx_callback_intf0() is not called for some reason (e.g. flaky hardware; the reproducer for this problem sometimes prevents usb_rx_callback_intf0() from being called), wait_for_completion_interruptible() in send_packet() never returns (i.e. hung task). As a workaround for such situation, change send_packet() to wait for completion with timeout of 10 seconds.
Product status
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 519737af11c03590819a6eec2ad532cfdb87ea63
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before f58ab83b7b7133e6baefe03a46846c4f6ce45e2f
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 26f6a1dd5d81ad61a875a747698da6f27abf389b
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 667afd4681781f60a644cd0d2ee6c59cb1c36208
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 8231e80118463be5598daaf266c1c83650f1948b
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 0213e4175abbb9dfcbf7c197e3817d527f459ad5
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before f7f3ecb4934fff782fa9bb1cd16e2290c041b22d
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before eecd203ada43a4693ce6fdd3a58ae10c7819252c
5.4.302 (semver)
5.10.247 (semver)
5.15.197 (semver)
6.1.159 (semver)
6.6.117 (semver)
6.12.58 (semver)
6.17.8 (semver)
6.18 (original_commit_for_fix)
References
git.kernel.org/...c/519737af11c03590819a6eec2ad532cfdb87ea63
git.kernel.org/...c/f58ab83b7b7133e6baefe03a46846c4f6ce45e2f
git.kernel.org/...c/26f6a1dd5d81ad61a875a747698da6f27abf389b
git.kernel.org/...c/667afd4681781f60a644cd0d2ee6c59cb1c36208
git.kernel.org/...c/8231e80118463be5598daaf266c1c83650f1948b
git.kernel.org/...c/0213e4175abbb9dfcbf7c197e3817d527f459ad5
git.kernel.org/...c/f7f3ecb4934fff782fa9bb1cd16e2290c041b22d
git.kernel.org/...c/eecd203ada43a4693ce6fdd3a58ae10c7819252c
Data based on CVE®. Copyright © 1999-2025, The MITRE Corporation. All rights reserved.
