On Wed, 21 Aug 2019, Alan Stern wrote: > The syzbot fuzzer has reported a pair of problems in the > hidraw_ioctl() function: slab-out-of-bounds read and use-after-free > read. An example of the first: > > BUG: KASAN: slab-out-of-bounds in strlen+0x79/0x90 lib/string.c:525 > Read of size 1 at addr ffff8881c8035f38 by task syz-executor.4/2833 > > CPU: 1 PID: 2833 Comm: syz-executor.4 Not tainted 5.3.0-rc2+ #1 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xca/0x13e lib/dump_stack.c:113 > print_address_description+0x6a/0x32c mm/kasan/report.c:351 > __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482 > kasan_report+0xe/0x12 mm/kasan/common.c:612 > strlen+0x79/0x90 lib/string.c:525 > strlen include/linux/string.h:281 [inline] > hidraw_ioctl+0x245/0xae0 drivers/hid/hidraw.c:446 > vfs_ioctl fs/ioctl.c:46 [inline] > file_ioctl fs/ioctl.c:509 [inline] > do_vfs_ioctl+0xd2d/0x1330 fs/ioctl.c:696 > ksys_ioctl+0x9b/0xc0 fs/ioctl.c:713 > __do_sys_ioctl fs/ioctl.c:720 [inline] > __se_sys_ioctl fs/ioctl.c:718 [inline] > __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:718 > do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x459829 > Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff > ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007f7a68f6dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829 > RDX: 0000000000000000 RSI: 0000000080404805 RDI: 0000000000000004 > RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a68f6e6d4 > R13: 00000000004c21de R14: 00000000004d5620 R15: 00000000ffffffff > > The two problems have the same cause: hidraw_ioctl() fails to test > whether the device has been removed. This patch adds the missing test. > > Reported-and-tested-by: syzbot+5a6c4ec678a0c6ee84ba@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Thanks a lot Alan for chasing this; I've applied the patch. -- Jiri Kosina SUSE Labs
