Control: tag -1 moreinfo On Fri, 2026-07-03 at 11:29 +0200, Julian Rilli wrote: > Package: src:linux > Version: 6.1.174-1 > Severity: important > > Dear Maintainer, > > After booting into 6.1.0-49-amd64, commands that access /proc or the > kernel ring buffer (dmesg -T, ps -ef, systemctl status) block > indefinitely, making the SSH session unresponsive.
How long did you actually wait, approximately? > The issue is triggered by: > sync; echo 3 > /proc/sys/vm/drop_caches > (run via cronjob every hour) > > This is a regression. Kernel 6.1.0-37-amd64 ran for 396 days with the > identical cronjob and configuration without any issues. > > Steps to reproduce: > 1. Boot 6.1.0-49-amd64 > 2. Run: sync; echo 3 > /proc/sys/vm/drop_caches > 3. Run: dmesg -T (or ps -ef, or systemctl status ssh) > 4. Command blocks indefinitely, SSH session becomes unresponsive > > Expected: Commands complete normally (as with 6.1.0-37) > Actual: Commands block, require new SSH session or reboot > > Workaround: Boot 6.1.0-37-amd64 or disable drop_caches cronjob. vm.drop_caches is an API for testing and not for production use, so I think it is a good idea to disable that cron job anyway. [...] > -- Package-specific info: > ** Kernel log: boot messages should be attached [...] Please provide a kernel log showing use of drop_caches and the subsequent hang. Also, the next version (package version 6.1.176-1, kernel version string 6.1.0-50-amd64) will be available very soon, so please test whether that fixes this for you. Ben. -- Ben Hutchings You can't have everything. Where would you put it?
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