From 077f526fe3cc4576fee6adc4c1ebded1ba0c518d Mon Sep 17 00:00:00 2001 From: lizhe Date: Thu, 18 Mar 2021 11:06:57 +0800 Subject: [PATCH] jffs2: Fix kasan slab-out-of-bounds problem commit 960b9a8a7676b9054d8b46a2c7db52a0c8766b56 upstream. KASAN report a slab-out-of-bounds problem. The logs are listed below. It is because in function jffs2_scan_dirent_node, we alloc "checkedlen+1" bytes for fd->name and we check crc with length rd->nsize. If checkedlen is less than rd->nsize, it will cause the slab-out-of-bounds problem. jffs2: Dirent at *** has zeroes in name. Truncating to %d char ================================================================== BUG: KASAN: slab-out-of-bounds in crc32_le+0x1ce/0x260 at addr ffff8800842cf2d1 Read of size 1 by task test_JFFS2/915 ============================================================================= BUG kmalloc-64 (Tainted: G B O ): kasan: bad access detected ----------------------------------------------------------------------------- INFO: Allocated in jffs2_alloc_full_dirent+0x2a/0x40 age=0 cpu=1 pid=915 ___slab_alloc+0x580/0x5f0 __slab_alloc.isra.24+0x4e/0x64 __kmalloc+0x170/0x300 jffs2_alloc_full_dirent+0x2a/0x40 jffs2_scan_eraseblock+0x1ca4/0x3b64 jffs2_scan_medium+0x285/0xfe0 jffs2_do_mount_fs+0x5fb/0x1bbc jffs2_do_fill_super+0x245/0x6f0 jffs2_fill_super+0x287/0x2e0 mount_mtd_aux.isra.0+0x9a/0x144 mount_mtd+0x222/0x2f0 jffs2_mount+0x41/0x60 mount_fs+0x63/0x230 vfs_kern_mount.part.6+0x6c/0x1f4 do_mount+0xae8/0x1940 SyS_mount+0x105/0x1d0 INFO: Freed in jffs2_free_full_dirent+0x22/0x40 age=27 cpu=1 pid=915 __slab_free+0x372/0x4e4 kfree+0x1d4/0x20c jffs2_free_full_dirent+0x22/0x40 jffs2_build_remove_unlinked_inode+0x17a/0x1e4 jffs2_do_mount_fs+0x1646/0x1bbc jffs2_do_fill_super+0x245/0x6f0 jffs2_fill_super+0x287/0x2e0 mount_mtd_aux.isra.0+0x9a/0x144 mount_mtd+0x222/0x2f0 jffs2_mount+0x41/0x60 mount_fs+0x63/0x230 vfs_kern_mount.part.6+0x6c/0x1f4 do_mount+0xae8/0x1940 SyS_mount+0x105/0x1d0 entry_SYSCALL_64_fastpath+0x1e/0x97 Call Trace: [] dump_stack+0x59/0x7e [] print_trailer+0x125/0x1b0 [] object_err+0x34/0x40 [] kasan_report.part.1+0x21f/0x534 [] ? vprintk+0x2d/0x40 [] ? crc32_le+0x1ce/0x260 [] kasan_report+0x26/0x30 [] __asan_load1+0x3d/0x50 [] crc32_le+0x1ce/0x260 [] ? jffs2_alloc_full_dirent+0x2a/0x40 [] jffs2_scan_eraseblock+0x1d0c/0x3b64 [] ? jffs2_scan_medium+0xccf/0xfe0 [] ? jffs2_scan_make_ino_cache+0x14c/0x14c [] ? kasan_unpoison_shadow+0x35/0x50 [] ? kasan_unpoison_shadow+0x35/0x50 [] ? kasan_kmalloc+0x5e/0x70 [] ? kmem_cache_alloc_trace+0x10c/0x2cc [] ? mtd_point+0xf7/0x130 [] jffs2_scan_medium+0x285/0xfe0 [] ? jffs2_scan_eraseblock+0x3b64/0x3b64 [] ? kasan_unpoison_shadow+0x35/0x50 [] ? kasan_unpoison_shadow+0x35/0x50 [] ? kasan_kmalloc+0x5e/0x70 [] ? __kmalloc+0x12b/0x300 [] ? kasan_kmalloc+0x5e/0x70 [] ? jffs2_sum_init+0x9f/0x240 [] jffs2_do_mount_fs+0x5fb/0x1bbc [] ? jffs2_del_noinode_dirent+0x640/0x640 [] ? kasan_kmalloc+0x5e/0x70 [] ? __init_rwsem+0x97/0xac [] jffs2_do_fill_super+0x245/0x6f0 [] jffs2_fill_super+0x287/0x2e0 [] ? jffs2_parse_options+0x594/0x594 [] mount_mtd_aux.isra.0+0x9a/0x144 [] mount_mtd+0x222/0x2f0 [] ? jffs2_parse_options+0x594/0x594 [] ? mount_mtd_aux.isra.0+0x144/0x144 [] ? free_pages+0x13/0x1c [] ? selinux_sb_copy_data+0x278/0x2e0 [] jffs2_mount+0x41/0x60 [] mount_fs+0x63/0x230 [] ? alloc_vfsmnt+0x32f/0x3b0 [] vfs_kern_mount.part.6+0x6c/0x1f4 [] do_mount+0xae8/0x1940 [] ? audit_filter_rules.constprop.6+0x1d10/0x1d10 [] ? copy_mount_string+0x40/0x40 [] ? alloc_pages_current+0xa4/0x1bc [] ? __get_free_pages+0x25/0x50 [] ? copy_mount_options.part.17+0x183/0x264 [] SyS_mount+0x105/0x1d0 [] ? copy_mnt_ns+0x560/0x560 [] ? msa_space_switch_handler+0x13d/0x190 [] entry_SYSCALL_64_fastpath+0x1e/0x97 [] ? msa_space_switch+0xb0/0xe0 Memory state around the buggy address: ffff8800842cf180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8800842cf200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8800842cf280: fc fc fc fc fc fc 00 00 00 00 01 fc fc fc fc fc ^ ffff8800842cf300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8800842cf380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Cc: stable@vger.kernel.org Reported-by: Kunkun Xu Signed-off-by: lizhe Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman --- fs/jffs2/scan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/jffs2/scan.c b/fs/jffs2/scan.c index 5f7e284e0df3..0b1a7f68b712 100644 --- a/fs/jffs2/scan.c +++ b/fs/jffs2/scan.c @@ -1078,7 +1078,7 @@ static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblo memcpy(&fd->name, rd->name, checkedlen); fd->name[checkedlen] = 0; - crc = crc32(0, fd->name, rd->nsize); + crc = crc32(0, fd->name, checkedlen); if (crc != je32_to_cpu(rd->name_crc)) { pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", __func__, ofs, je32_to_cpu(rd->name_crc), crc);