Re: [PATCH 0/1] lib: validate in-memory LZ4 chunk length

[Andrew Morton]

On Sat, 12 Sep 2026 21:32:16 +0800 Zhiling Zou <zhilinz@xxxxxxxxxx> wrote:

> Hi Linux kernel maintainers,
> 
> We found and validated an issue in lib/decompress_unlz4.c.

Thanks.

> The bug is
> reachable by a root user through kexec_file_load() with a crafted
> external initrd.
> 
> We've tested it, and it should not affect any other functionality.

OK.  I don't feel that a cc:stable backport is justified for this.  If
there was (or even might be) a non-root callsite then yes, backport it.

Do you agree that these:

hp2:/usr/src/linux-7.3-rc1> grep -rl unlz4 .
./lib/decompress_unlz4.c
./lib/Makefile
./lib/decompress.c
./scripts/sbom/tests/cmd_graph/test_savedcmd_parser.py
./include/linux/decompress/unlz4.h
./arch/parisc/boot/compressed/misc.c
./arch/mips/boot/compressed/decompress.c
./arch/s390/boot/decompressor.c
./arch/x86/boot/compressed/misc.c
./arch/arm/boot/compressed/decompress.c
hp2:/usr/src/linux-7.3-rc1> 

are the only callers?