On Thu, Jan 04, 2018 at 08:58:02AM -0800, syzbot wrote: > Hello, > > syzkaller hit the following crash on > 71ee203389f7cb1c1927eab22b95baa01405791c > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+37db7b2a61b64a9ab...@syzkaller.appspotmail.com > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > audit: type=1400 audit(1514753657.623:7): avc: denied { map } for > pid=3504 comm="syzkaller926656" path="/root/syzkaller926656864" dev="sda1" > ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 > tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 > ================================================================== > BUG: KASAN: slab-out-of-bounds in cap_inode_getsecurity+0x621/0x7d0 > security/commoncap.c:408 > Read of size 4 at addr ffff8801bea30b00 by task syzkaller926656/3504 > > CPU: 1 PID: 3504 Comm: syzkaller926656 Not tainted 4.15.0-rc5+ #244 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:53 > print_address_description+0x73/0x250 mm/kasan/report.c:252 > kasan_report_error mm/kasan/report.c:351 [inline] > kasan_report+0x25b/0x340 mm/kasan/report.c:409 > __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 > cap_inode_getsecurity+0x621/0x7d0 security/commoncap.c:408 > security_inode_getsecurity+0xcd/0x110 security/security.c:809 > xattr_getsecurity+0xd3/0x1f0 fs/xattr.c:244 > vfs_getxattr+0xc8/0x110 fs/xattr.c:333 > getxattr+0x116/0x2a0 fs/xattr.c:540 > path_getxattr+0xed/0x170 fs/xattr.c:568 > SYSC_getxattr fs/xattr.c:580 [inline] > SyS_getxattr+0x33/0x40 fs/xattr.c:577 > entry_SYSCALL_64_fastpath+0x23/0x9a
Already fixed in Linus's tree. #syz fix: capabilities: fix buffer overread on very short xattr