On Wed, 19 Jun 2019, syzbot wrote: > syzbot has found a reproducer for the following crash on: > > HEAD commit: 9939f56e 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=135e29faa00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=df134eda130bb43a > dashboard link: https://syzkaller.appspot.com/bug?extid=6d237e74cdc13f036473 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=175d946ea00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+6d237e74cdc13f036473@xxxxxxxxxxxxxxxxxxxxxxxxx > > usb 3-1: Direct firmware load for isl3887usb failed with error -2 > usb 3-1: Firmware not found. > ================================================================== > BUG: KASAN: slab-out-of-bounds in p54u_load_firmware_cb.cold+0x97/0x13d > drivers/net/wireless/intersil/p54/p54usb.c:936 > Read of size 8 at addr ffff8881c9cf7588 by task kworker/1:5/2759 > > CPU: 1 PID: 2759 Comm: kworker/1:5 Not tainted 5.2.0-rc5+ #11 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Workqueue: events request_firmware_work_func > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xca/0x13e lib/dump_stack.c:113 > print_address_description+0x67/0x231 mm/kasan/report.c:188 > __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:317 > kasan_report+0xe/0x20 mm/kasan/common.c:614 > p54u_load_firmware_cb.cold+0x97/0x13d > drivers/net/wireless/intersil/p54/p54usb.c:936 > request_firmware_work_func+0x126/0x242 > drivers/base/firmware_loader/main.c:785 > process_one_work+0x905/0x1570 kernel/workqueue.c:2269 > worker_thread+0x96/0xe20 kernel/workqueue.c:2415 > kthread+0x30b/0x410 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > Allocated by task 1612: > save_stack+0x1b/0x80 mm/kasan/common.c:71 > set_track mm/kasan/common.c:79 [inline] > __kasan_kmalloc mm/kasan/common.c:489 [inline] > __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:462 > kmalloc include/linux/slab.h:547 [inline] > syslog_print kernel/printk/printk.c:1346 [inline] > do_syslog kernel/printk/printk.c:1519 [inline] > do_syslog+0x4f4/0x12e0 kernel/printk/printk.c:1493 > kmsg_read+0x8a/0xb0 fs/proc/kmsg.c:40 > proc_reg_read+0x1c1/0x280 fs/proc/inode.c:221 > __vfs_read+0x76/0x100 fs/read_write.c:425 > vfs_read+0x18e/0x3d0 fs/read_write.c:461 > ksys_read+0x127/0x250 fs/read_write.c:587 > do_syscall_64+0xb7/0x560 arch/x86/entry/common.c:301 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 1612: > save_stack+0x1b/0x80 mm/kasan/common.c:71 > set_track mm/kasan/common.c:79 [inline] > __kasan_slab_free+0x130/0x180 mm/kasan/common.c:451 > slab_free_hook mm/slub.c:1421 [inline] > slab_free_freelist_hook mm/slub.c:1448 [inline] > slab_free mm/slub.c:2994 [inline] > kfree+0xd7/0x280 mm/slub.c:3949 > syslog_print kernel/printk/printk.c:1405 [inline] > do_syslog kernel/printk/printk.c:1519 [inline] > do_syslog+0xff3/0x12e0 kernel/printk/printk.c:1493 > kmsg_read+0x8a/0xb0 fs/proc/kmsg.c:40 > proc_reg_read+0x1c1/0x280 fs/proc/inode.c:221 > __vfs_read+0x76/0x100 fs/read_write.c:425 > vfs_read+0x18e/0x3d0 fs/read_write.c:461 > ksys_read+0x127/0x250 fs/read_write.c:587 > do_syscall_64+0xb7/0x560 arch/x86/entry/common.c:301 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8881c9cf7180 > which belongs to the cache kmalloc-1k of size 1024 > The buggy address is located 8 bytes to the right of > 1024-byte region [ffff8881c9cf7180, ffff8881c9cf7580) > The buggy address belongs to the page: > page:ffffea0007273d00 refcount:1 mapcount:0 mapping:ffff8881dac02a00 > index:0x0 compound_mapcount: 0 > flags: 0x200000000010200(slab|head) > raw: 0200000000010200 dead000000000100 dead000000000200 ffff8881dac02a00 > raw: 0000000000000000 00000000000e000e 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8881c9cf7480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8881c9cf7500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8881c9cf7580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ^ > ffff8881c9cf7600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8881c9cf7680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== Isn't this the same as syzkaller bug 200d4bb11b23d929335f ? Doesn't the same patch fix it? Alan Stern
