Description

In the Linux kernel, the following vulnerability has been resolved: zram: do not forget to endio for partial discard requests As reported by Qu Wenruo and Avinesh Kumar, the following getconf PAGESIZE 65536 blkdiscard -p 4k /dev/zram0 takes literally forever to complete. zram doesn't support partial discards and just returns immediately w/o doing any discard work in such cases. The problem is that we forget to endio on our way out, so blkdiscard sleeps forever in submit_bio_wait(). Fix this by jumping to end_bio label, which does bio_endio().

References 5

• git.kernel.org https://git.kernel.org/stable/c/2d1f18efccdb8b29552399d024c36b705447e975
• git.kernel.org https://git.kernel.org/stable/c/35d3300f6357cfaa72db2721dc2b345b19bac5df
• git.kernel.org https://git.kernel.org/stable/c/68ce397e8236088fc53b9532d383a722288c8194
• git.kernel.org https://git.kernel.org/stable/c/a02363f71a79b755daa78a70d6b217f9c13c8c85
• git.kernel.org https://git.kernel.org/stable/c/e3668b371329ea036ff022ce8ecc82f8befcf003

Remediation