When rebuilding from source EROFS images, erofs_read_xattrs_from_disk() is called for inodes that have xattr. At that point inode->sbi points to the source image's sbi, which is opened read-only and never gets erofs_xattr_init(), so sbi->xamgr is NULL. get_xattritem(sbi) then dereferences xamgr and crashes with SIGSEGV.
Fix by using the build target's xamgr when initializing src's sbi. Reported-by: Yixiao Chen <[email protected]> Fixes: https://github.com/erofs/erofs-utils/issues/42 Signed-off-by: lishixian <[email protected]> Reviewed-by: Yifan Zhao <[email protected]> --- lib/rebuild.c | 1 + mkfs/main.c | 1 + 2 files changed, 2 insertions(+) diff --git a/lib/rebuild.c b/lib/rebuild.c index f89a17c..f1e79c1 100644 --- a/lib/rebuild.c +++ b/lib/rebuild.c @@ -437,6 +437,7 @@ int erofs_rebuild_load_tree(struct erofs_inode *root, struct erofs_sb_info *sbi, erofs_err("failed to read superblock of %s", fsid); return ret; } + sbi->xamgr = g_sbi.xamgr; inode.nid = sbi->root_nid; inode.sbi = sbi; diff --git a/mkfs/main.c b/mkfs/main.c index b84d1b4..cb0f0cc 100644 --- a/mkfs/main.c +++ b/mkfs/main.c @@ -1011,6 +1011,7 @@ static void erofs_rebuild_cleanup(void) list_for_each_entry_safe(src, n, &rebuild_src_list, list) { list_del(&src->list); + src->xamgr = NULL; /* borrowed from g_sbi, do not free */ erofs_put_super(src); erofs_dev_close(src); free(src); -- 2.47.3
