14-Sep-2026 16:43:09: building syzkaller on 0ac7291ca51f87df8022da0f66178546e855701a... 14-Sep-2026 16:43:25: fetching kernel... 14-Sep-2026 16:43:27: checked out kernel commit 5bfe2b8c1439354d25dc5b1779cd0bb75bb90a7f ("Revert \"mmc: sdhci: make tuning_err a signed int\"", 2026-09-11 15:56:56 +0000 UTC) 14-Sep-2026 16:43:27: cleaning kernel... 14-Sep-2026 16:43:28: building kernel... 14-Sep-2026 16:46:30: kernel built successfully with compiler Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 14-Sep-2026 16:46:30: testing patch... 14-Sep-2026 16:49:29: reproduced crash: UBSAN: shift-out-of-bounds in ext4_fill_super