Hi, I encountered a kernel WARNING in the function bdev_getblk() when fuzzing the Linux 6.12 kernel using Syzkaller. The crash occurs during a block buffer allocation path, where __alloc_pages_noprof() fails under memory pressure, and triggers a WARNING due to an internal allocation failure. Root Cause: Code Path: The failure originates from the function bdev_getblk() in fs/buffer.c, which attempts to allocate a new buffer via grow_buffers() → grow_dev_folio() → __filemap_get_folio(). Memory Allocation Failure: Under specific memory pressure and vm.zone_reclaim_mode settings, the internal call to alloc_pages() in __alloc_pages_noprof() fails, resulting in the observed warning. I recommend reviewing the block buffer allocation path in bdev_getblk(), particularly how it handles allocation failures under memory pressure. This can be reproduced on: HEAD commit: commit adc218676eef25575469234709c2d87185ca223a report: https://pastebin.com/raw/wqAeZJxF console output : https://pastebin.com/raw/aLaVQpzR kernel config : https://pastebin.com/x48ijkN8 C reproducer : https://pastebin.com/raw/whJgYnHk Best regards, Xianying
