On Mon, Aug 12, 2019 at 02:06:08PM +0200, Andrey Konovalov wrote: > On Thu, Aug 8, 2019 at 2:38 PM syzbot > <syzbot+45b2f40f0778cfa7634e@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit: e96407b4 usb-fuzzer: main usb gadget fuzzer driver > > git tree: https://github.com/google/kasan.git usb-fuzzer > > console output: https://syzkaller.appspot.com/x/log.txt?x=13aeaece600000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=cfa2c18fb6a8068e > > dashboard link: https://syzkaller.appspot.com/bug?extid=45b2f40f0778cfa7634e > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > > > Unfortunately, I don't have any reproducer for this crash yet. > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+45b2f40f0778cfa7634e@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ldusb 6-1:0.124: Read buffer overflow, -131383996186150 bytes dropped > > usercopy: Kernel memory exposure attempt detected from SLUB > > object 'kmalloc-2k' (offset 8, size 65062)! > > ------------[ cut here ]------------ > > kernel BUG at mm/usercopy.c:98! > > invalid opcode: 0000 [#1] SMP KASAN > > CPU: 0 PID: 15185 Comm: syz-executor.2 Not tainted 5.3.0-rc2+ #25 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > RIP: 0010:usercopy_abort+0xb9/0xbb mm/usercopy.c:98 > > Code: e8 c1 f7 d6 ff 49 89 d9 4d 89 e8 4c 89 e1 41 56 48 89 ee 48 c7 c7 e0 > > f3 cd 85 ff 74 24 08 41 57 48 8b 54 24 20 e8 15 98 c1 ff <0f> 0b e8 95 f7 > > d6 ff e8 80 9f fd ff 8b 54 24 04 49 89 d8 4c 89 e1 > > RSP: 0018:ffff8881ccb3fc38 EFLAGS: 00010286 > > RAX: 0000000000000067 RBX: ffffffff86a659d4 RCX: 0000000000000000 > > RDX: 0000000000000000 RSI: ffffffff8128a0fd RDI: ffffed1039967f79 > > RBP: ffffffff85cdf2c0 R08: 0000000000000067 R09: fffffbfff11acdaa > > R10: fffffbfff11acda9 R11: ffffffff88d66d4f R12: ffffffff86a696e8 > > R13: ffffffff85cdf180 R14: 000000000000fe26 R15: ffffffff85cdf140 > > FS: 00007ff6daf91700(0000) GS:ffff8881db200000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 00007f1de6600000 CR3: 00000001ca554000 CR4: 00000000001406f0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > Call Trace: > > __check_heap_object+0xdd/0x110 mm/slub.c:3914 > > check_heap_object mm/usercopy.c:234 [inline] > > __check_object_size mm/usercopy.c:280 [inline] > > __check_object_size+0x32d/0x39b mm/usercopy.c:250 > > check_object_size include/linux/thread_info.h:119 [inline] > > check_copy_size include/linux/thread_info.h:150 [inline] > > copy_to_user include/linux/uaccess.h:151 [inline] > > ld_usb_read+0x304/0x780 drivers/usb/misc/ldusb.c:495 > > #syz dup: KASAN: use-after-free Read in ld_usb_release This was a different bug. Mark as dup of the latest report: #syz dup: KASAN: slab-out-of-bounds Read in ld_usb_read (3) Johan
