ng, as shown below: erofs: (device dm-1): z_erofs_pcluster_begin: failed to get inline data -4 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 ... pc : z_erofs_decompress_queue+0x4c8/0xa14 lr : z_erofs_decompress_queue+0x160/0xa14 sp : ffffffc08b3eb3a0 x29: ffffffc08b3eb570 x28: ffffffc08b3eb418 x27: 0000000000001000 x26: ffffff8086ebdbb8 x25: ffffff8086ebdbb8 x24: 0000000000000001 x23: 0000000000000008 x22: 00000000fffffffb x21: dead000000000700 x20: 00000000000015e7 x19: ffffff808babb400 x18: ffffffc089edc098 x17: 00000000c006287d x16: 00000000c006287d x15: 0000000000000004 x14: ffffff80ba8f8000 x13: 0000000000000004 x12: 00000006589a77c9 x11: 0000000000000015 x10: 0000000000000000 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : ffffffffffffffe0 x3 : 0000000000000020 x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: z_erofs_decompress_queue+0x4c8/0xa14 z_erofs_runqueue+0x908/0x97c z_erofs_read_folio+0x128/0x228 filemap_read_folio+0x68/0x128 filemap_get_pages+0x44c/0x8b4 filemap_read+0x12c/0x5b8 generic_file_read_iter+0x4c/0x15c do_iter_readv_writev+0x188/0x1e0 vfs_iter_read+0xac/0x1a4 backing_file_read_iter+0x170/0x34c ovl_read_iter+0xf0/0x140 vfs_read+0x28c/0x344 ksys_read+0x80/0xf0 __arm64_sys_read+0x24/0x34 invoke_syscall+0x60/0x114 el0_svc_common+0x88/0xe4 do_el0_svc+0x24/0x30 el0_svc+0x40/0xa8 el0t_64_sync_handler+0x70/0xbc el0t_64_sync+0x1bc/0x1c0 Fix this by reading the inline data before allocating and adding the pclusters to the I/O chains. Fixes: cecf864d3d76 ("erofs: support inline data decompression") Reported-by: Zhiguo Niu Reviewed-and-tested-by: Zhiguo Niu Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin --- fs/erofs/zdata.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index 683703aee5ef2..98e44570841a3 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -805,14 +805,26 @@ static int z_erofs_pcluster_begin(struct z_erofs_frontend *fe) struct erofs_map_blocks *map = &fe->map; struct super_block *sb = fe->inode->i_sb; struct z_erofs_pcluster *pcl = NULL; - void *ptr; + void *ptr = NULL; int ret; DBG_BUGON(fe->pcl); /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous pcluster */ DBG_BUGON(!fe->head); - if (!(map->m_flags & EROFS_MAP_META)) { + if (map->m_flags & EROFS_MAP_META) { + ret = erofs_init_metabuf(&map->buf, sb, + erofs_inode_in_metabox(fe->inode)); + if (ret) + return ret; + ptr = erofs_bread(&map->buf, map->m_pa, false); + if (IS_ERR(ptr)) { + erofs_err(sb, "failed to read inline data %pe @ pa %llu of nid %llu", + ptr, map->m_pa, EROFS_I(fe->inode)->nid); + return PTR_ERR(ptr); + } + ptr = map->buf.page; + } else { while (1) { rcu_read_lock(); pcl = xa_load(&EROFS_SB(sb)->managed_pslots, map->m_pa); @@ -852,18 +864,8 @@ static int z_erofs_pcluster_begin(struct z_erofs_frontend *fe) /* bind cache first when cached decompression is preferred */ z_erofs_bind_cache(fe); } else { - ret = erofs_init_metabuf(&map->buf, sb, - erofs_inode_in_metabox(fe->inode)); - if (ret) - return ret; - ptr = erofs_bread(&map->buf, map->m_pa, false); - if (IS_ERR(ptr)) { - ret = PTR_ERR(ptr); - erofs_err(sb, "failed to get inline folio %d", ret); - return ret; - } - folio_get(page_folio(map->buf.page)); - WRITE_ONCE(fe->pcl->compressed_bvecs[0].page, map->buf.page); + folio_get(page_folio((struct page *)ptr)); + WRITE_ONCE(fe->pcl->compressed_bvecs[0].page, ptr); fe->pcl->pageofs_in = map->m_pa & ~PAGE_MASK; fe->mode = Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE; } -- 2.51.0[PATCH 6.18 031/641] erofs: fix inline data read failure for ztailpacking pclustersGreg Kroah-Hartman undefinedstable@vger.kernel.org undefined undefined undefined undefined undefined”@†•^