lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Sun, 28 Jun 2020 16:16:23 +0530 From: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org> To: bjorn.andersson@...aro.org Cc: davem@...emloft.net, kuba@...nel.org, linux-kernel@...r.kernel.org, netdev@...r.kernel.org, syzkaller-bugs@...glegroups.com Subject: Re: KASAN: slab-out-of-bounds Read in qrtr_endpoint_post Hi Bjorn, On Sat, Jun 27, 2020 at 01:57:13PM -0700, syzbot wrote: > syzbot has found a reproducer for the following crash on: > > HEAD commit: 1590a2e1 Merge tag 'acpi-5.8-rc3' of git://git.kernel.org/.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=14b2b503100000 > kernel config: https://syzkaller.appspot.com/x/.config?x=bf3aec367b9ab569 > dashboard link: https://syzkaller.appspot.com/bug?extid=b8fe393f999a291a9ea6 > compiler: gcc (GCC) 10.1.0-syz 20200507 > userspace arch: i386 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=109e6b55100000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13671a3d100000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+b8fe393f999a291a9ea6@...kaller.appspotmail.com > > ================================================================== > BUG: KASAN: slab-out-of-bounds in qrtr_endpoint_post+0xeeb/0x1010 net/qrtr/qrtr.c:462 > Read of size 2 at addr ffff88809de50c48 by task syz-executor531/6806 > > CPU: 0 PID: 6806 Comm: syz-executor531 Not tainted 5.8.0-rc2-syzkaller #0 > 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+0x18f/0x20d lib/dump_stack.c:118 > print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383 > __kasan_report mm/kasan/report.c:513 [inline] > kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 > qrtr_endpoint_post+0xeeb/0x1010 net/qrtr/qrtr.c:462 > qrtr_tun_write_iter+0xf5/0x180 net/qrtr/tun.c:92 Hmm. Is this due to the fact that we are not checking the length of the kbuf allocated in qrtr_tun_write_iter()? The length derived from 'iov_iter_count(from)' gets used directly and that might be causing the out of bound access error here. Thanks, Mani > call_write_iter include/linux/fs.h:1907 [inline] > do_iter_readv_writev+0x567/0x780 fs/read_write.c:694 > do_iter_write+0x188/0x5f0 fs/read_write.c:999 > compat_writev+0x1ea/0x390 fs/read_write.c:1352 > do_compat_pwritev64+0x180/0x1b0 fs/read_write.c:1401 > do_syscall_32_irqs_on+0x3f/0x60 arch/x86/entry/common.c:403 > __do_fast_syscall_32 arch/x86/entry/common.c:448 [inline] > do_fast_syscall_32+0x7f/0x120 arch/x86/entry/common.c:474 > entry_SYSENTER_compat+0x6d/0x7c arch/x86/entry/entry_64_compat.S:138 > RIP: 0023:0xf7f8f569 > Code: Bad RIP value. > RSP: 002b:00000000ffda5ffc EFLAGS: 00000292 ORIG_RAX: 000000000000014e > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000440 > RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00000000080bb528 > RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > Allocated by task 6806: > save_stack+0x1b/0x40 mm/kasan/common.c:48 > set_track mm/kasan/common.c:56 [inline] > __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 > __do_kmalloc mm/slab.c:3656 [inline] > __kmalloc+0x17a/0x340 mm/slab.c:3665 > kmalloc include/linux/slab.h:560 [inline] > kzalloc include/linux/slab.h:669 [inline] > qrtr_tun_write_iter+0x8a/0x180 net/qrtr/tun.c:83 > call_write_iter include/linux/fs.h:1907 [inline] > do_iter_readv_writev+0x567/0x780 fs/read_write.c:694 > do_iter_write+0x188/0x5f0 fs/read_write.c:999 > compat_writev+0x1ea/0x390 fs/read_write.c:1352 > do_compat_pwritev64+0x180/0x1b0 fs/read_write.c:1401 > do_syscall_32_irqs_on+0x3f/0x60 arch/x86/entry/common.c:403 > __do_fast_syscall_32 arch/x86/entry/common.c:448 [inline] > do_fast_syscall_32+0x7f/0x120 arch/x86/entry/common.c:474 > entry_SYSENTER_compat+0x6d/0x7c arch/x86/entry/entry_64_compat.S:138 > > Freed by task 1: > save_stack+0x1b/0x40 mm/kasan/common.c:48 > set_track mm/kasan/common.c:56 [inline] > kasan_set_free_info mm/kasan/common.c:316 [inline] > __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 > __cache_free mm/slab.c:3426 [inline] > kfree+0x103/0x2c0 mm/slab.c:3757 > tomoyo_path_perm+0x234/0x3f0 security/tomoyo/file.c:842 > security_inode_getattr+0xcf/0x140 security/security.c:1278 > vfs_getattr fs/stat.c:121 [inline] > vfs_statx+0x170/0x390 fs/stat.c:206 > vfs_lstat include/linux/fs.h:3301 [inline] > __do_sys_newlstat+0x91/0x110 fs/stat.c:374 > do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > The buggy address belongs to the object at ffff88809de50c40 > which belongs to the cache kmalloc-32 of size 32 > The buggy address is located 8 bytes inside of > 32-byte region [ffff88809de50c40, ffff88809de50c60) > The buggy address belongs to the page: > page:ffffea0002779400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88809de50fc1 > flags: 0xfffe0000000200(slab) > raw: 00fffe0000000200 ffffea000277e008 ffffea0002761c88 ffff8880aa0001c0 > raw: ffff88809de50fc1 ffff88809de50000 000000010000003f 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff88809de50b00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc > ffff88809de50b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc > >ffff88809de50c00: fb fb fb fb fc fc fc fc 04 fc fc fc fc fc fc fc > ^ > ffff88809de50c80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc > ffff88809de50d00: fb fb fb fb fc fc fc fc 00 01 fc fc fc fc fc fc > ================================================================== >
Powered by blists - more mailing lists