Michael Chang via Grub-devel <grub-devel@gnu.org> on Fri, 2025/02/21 09:06: > Previously, the number of extent entries was not properly capped based > on the actual available space. This could lead to insufficient reads for > external extents, since the computation was based solely on the inline > extent layout. > > In this patch, when processing the extent header, we determine whether > the header is stored inline (i.e., at inode->blocks.dir_blocks) or in an > external extent block. We then clamp the number of entries accordingly > (using max_inline_ext for inline extents and max_external_ext for > external extent blocks). > > This change ensures that only the valid number of extent entries is > processed, preventing out-of-bound reads and potential filesystem > corruption. > > Fixes: 7e2f750f0a (fs/ext2: Fix out-of-bounds read for inline extents) > > Signed-off-by: Michael Chang <mch...@suse.com>
Tested and it fixes reading from loopback disk on ext4 for me. Thanks!
Tested-by: Christian Hesse <m...@eworm.de>
--
main(a){char*c=/* Schoene Gruesse */"B?IJj;MEH"
"CX:;",b;for(a/* Best regards my address: */=0;b=c[a++];)
putchar(b-1/(/* Chris cc -ox -xc - && ./x */b/42*2-3)*42);}
pgpX8bKcjOdnQ.pgp
Description: OpenPGP digital signature
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