Tadeusz Struk c504167adc exfat: check if cluster num is valid ... commit 64ba4b15e5 upstream. Syzbot reported slab-out-of-bounds read in exfat_clear_bitmap. This was triggered by reproducer calling truncute with size 0, which causes the following trace: BUG: KASAN: slab-out-of-bounds in exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174 Read of size 8 at addr ffff888115aa9508 by task syz-executor251/365 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3c0 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report+0x1a4/0x1f0 mm/kasan/report.c:436 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174 exfat_free_cluster+0x25a/0x4a0 fs/exfat/fatent.c:181 __exfat_truncate+0x99e/0xe00 fs/exfat/file.c:217 exfat_truncate+0x11b/0x4f0 fs/exfat/file.c:243 exfat_setattr+0xa03/0xd40 fs/exfat/file.c:339 notify_change+0xb76/0xe10 fs/attr.c:336 do_truncate+0x1ea/0x2d0 fs/open.c:65 Move the is_valid_cluster() helper from fatent.c to a common header to make it reusable in other *.c files. And add is_valid_cluster() to validate if cluster number is within valid range in exfat_clear_bitmap() and exfat_set_bitmap(). Link: https://syzkaller.appspot.com/bug?id=50381fc73821ecae743b8cf24b4c9a04776f767c Reported-by: syzbot+a4087e40b9c13aad7892@syzkaller.appspotmail.com Fixes: 1e49a94cf7 ("exfat: add bitmap operations") Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-06-06 08:43:37 +02:00
..
Kconfig	exfat: Improve wording of EXFAT_DEFAULT_IOCHARSET config option	2020-06-09 16:48:39 +09:00
Makefile	exfat: add Kconfig and Makefile	2020-03-05 21:00:40 -05:00
balloc.c	exfat: check if cluster num is valid	2022-06-06 08:43:37 +02:00
cache.c	exfat: fix use of uninitialized spinlock on error path	2020-10-07 14:27:13 +09:00
dir.c	exfat: handle wrong stream entry size in exfat_readdir()	2021-07-04 09:33:00 +09:00
exfat_fs.h	exfat: check if cluster num is valid	2022-06-06 08:43:37 +02:00
exfat_raw.h	exfat: fix shift-out-of-bounds in exfat_fill_super()	2021-02-22 09:55:13 +09:00
fatent.c	exfat: check if cluster num is valid	2022-06-06 08:43:37 +02:00
file.c	exfat: fix i_blocks for files truncated over 4 GiB	2022-03-08 19:12:32 +01:00
inode.c	exfat: fix i_blocks for files truncated over 4 GiB	2022-03-08 19:12:32 +01:00
misc.c	exfat: write multiple sectors at once	2020-08-12 08:31:11 +09:00
namei.c	exfat: reuse exfat_inode_info variable instead of calling EXFAT_I()	2022-03-08 19:12:31 +01:00
nls.c	exfat: Avoid allocating upcase table using kcalloc()	2020-12-22 12:31:17 +09:00
super.c	exfat: fix i_blocks for files truncated over 4 GiB	2022-03-08 19:12:32 +01:00