From: Gao Xiang <hsiangkao@linux.alibaba.com> mainline inclusion from mainline-v7.1 commit 2d8c7edcb661812249469f4a5b62e9339118846f category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15717 CVE: CVE-2026-53015 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- As sashiko reported [1], `lcn` was typed as `unsigned long` (or `unsigned int` sometimes), which is only 32 bits wide on 32-bit platforms, which causes `(lcn << lclusterbits)` to be truncated at 4 GiB. In order to consolidate the logic, just use `u64` consistently around the codebase. [1] https://sashiko.dev/r/20260420034612.1899973-1-hsiangkao%40linux.alibaba.com Fixes: 152a333a5895 ("staging: erofs: add compacted compression indexes support") Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> [context conflicts] Signed-off-by: Yipeng Zou <zouyipeng@huawei.com> --- fs/erofs/zmap.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c index 0603ccd00b3c..d6ada723ffae 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -12,7 +12,7 @@ struct z_erofs_maprecorder { struct erofs_map_blocks *map; void *kaddr; - unsigned long lcn; + u64 lcn; /* compression extent information gathered */ u8 type, headtype; u16 clusterofs; @@ -23,7 +23,7 @@ struct z_erofs_maprecorder { }; static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m, - unsigned long lcn) + u64 lcn) { struct inode *const inode = m->inode; struct erofs_inode *const vi = EROFS_I(inode); @@ -219,7 +219,7 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m, } static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m, - unsigned long lcn, bool lookahead) + u64 lcn, bool lookahead) { struct inode *const inode = m->inode; struct erofs_inode *const vi = EROFS_I(inode); @@ -270,7 +270,7 @@ static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m, } static int z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder *m, - unsigned int lcn, bool lookahead) + u64 lcn, bool lookahead) { struct erofs_inode *vi = EROFS_I(m->inode); int err; @@ -301,7 +301,7 @@ static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m, const unsigned int lclusterbits = vi->z_logical_clusterbits; while (m->lcn >= lookback_distance) { - unsigned long lcn = m->lcn - lookback_distance; + u64 lcn = m->lcn - lookback_distance; int err; err = z_erofs_load_lcluster_from_disk(m, lcn, false); @@ -321,14 +321,14 @@ static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m, m->map->m_la = (lcn << lclusterbits) | m->clusterofs; return 0; default: - erofs_err(sb, "unknown type %u @ lcn %lu of nid %llu", + erofs_err(sb, "unknown type %u @ lcn %llu of nid %llu", m->type, lcn, vi->nid); DBG_BUGON(1); return -EOPNOTSUPP; } } err_bogus: - erofs_err(sb, "bogus lookback distance %u @ lcn %lu of nid %llu", + erofs_err(sb, "bogus lookback distance %u @ lcn %llu of nid %llu", lookback_distance, m->lcn, vi->nid); DBG_BUGON(1); return -EFSCORRUPTED; @@ -341,7 +341,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, struct erofs_inode *const vi = EROFS_I(m->inode); struct erofs_map_blocks *const map = m->map; const unsigned int lclusterbits = vi->z_logical_clusterbits; - unsigned long lcn; + u64 lcn; int err; DBG_BUGON(m->type != Z_EROFS_LCLUSTER_TYPE_PLAIN && @@ -393,7 +393,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, break; fallthrough; default: - erofs_err(sb, "cannot found CBLKCNT @ lcn %lu of nid %llu", lcn, + erofs_err(sb, "cannot found CBLKCNT @ lcn %llu of nid %llu", lcn, vi->nid); DBG_BUGON(1); return -EFSCORRUPTED; @@ -402,7 +402,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, map->m_plen = erofs_pos(sb, m->compressedblks); return 0; err_bonus_cblkcnt: - erofs_err(sb, "bogus CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid); + erofs_err(sb, "bogus CBLKCNT @ lcn %llu of nid %llu", lcn, vi->nid); DBG_BUGON(1); return -EFSCORRUPTED; } -- 2.34.1