On 9/16/25 16:48, Gao Xiang wrote: > Since all real encoded extents (directly handled by the decompression > subsystem) have a sane, limited maximum decoded length > (Z_EROFS_PCLUSTER_MAX_DSIZE), and the read‑more policy is only applied > if needed. > > However, it makes no sense to read more for non‑encoded maps, such as > fragment extents, since such extents can be huge (up to i_size) and > there is no benefit to reading more at this layer. > > For normal images, it does not really matter, but for crafted images > generated by syzbot, excessively large fragment extents can cause > read‑more to run for an overly long time. > > Reported-by: [email protected] > Closes: https://lore.kernel.org/r/[email protected] > Fixes: b44686c8391b ("erofs: fix large fragment handling") > Fixes: b15b2e307c3a ("erofs: support on-disk compressed fragments data") > Signed-off-by: Gao Xiang <[email protected]>
Reviewed-by: Chao Yu <[email protected]> Thanks,
