3.16.81-rc1 review patch. If anyone has any objections, please let me know.
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From: YueHaibing yuehaibing@huawei.com
commit dea37a97265588da604c6ba80160a287b72c7bfd upstream.
Syzkaller report this:
BUG: KASAN: use-after-free in sysfs_remove_file_ns+0x5f/0x70 fs/sysfs/file.c:468 Read of size 8 at addr ffff8881f59a6b70 by task syz-executor.0/8363
CPU: 0 PID: 8363 Comm: syz-executor.0 Not tainted 5.0.0-rc8+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xfa/0x1ce lib/dump_stack.c:113 print_address_description+0x65/0x270 mm/kasan/report.c:187 kasan_report+0x149/0x18d mm/kasan/report.c:317 sysfs_remove_file_ns+0x5f/0x70 fs/sysfs/file.c:468 sysfs_remove_file include/linux/sysfs.h:519 [inline] driver_remove_file+0x40/0x50 drivers/base/driver.c:122 usb_remove_newid_files drivers/usb/core/driver.c:212 [inline] usb_deregister+0x12a/0x3b0 drivers/usb/core/driver.c:1005 cpia2_exit+0xa/0x16 [cpia2] __do_sys_delete_module kernel/module.c:1018 [inline] __se_sys_delete_module kernel/module.c:961 [inline] __x64_sys_delete_module+0x3dc/0x5e0 kernel/module.c:961 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x462e99 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f86f3754c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000300 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f86f37556bc R13: 00000000004bcca9 R14: 00000000006f6b48 R15: 00000000ffffffff
Allocated by task 8363: set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc.constprop.3+0xa0/0xd0 mm/kasan/common.c:495 kmalloc include/linux/slab.h:545 [inline] kzalloc include/linux/slab.h:740 [inline] bus_add_driver+0xc0/0x610 drivers/base/bus.c:651 driver_register+0x1bb/0x3f0 drivers/base/driver.c:170 usb_register_driver+0x267/0x520 drivers/usb/core/driver.c:965 0xffffffffc1b4817c do_one_initcall+0xfa/0x5ca init/main.c:887 do_init_module+0x204/0x5f6 kernel/module.c:3460 load_module+0x66b2/0x8570 kernel/module.c:3808 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 8363: set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x130/0x180 mm/kasan/common.c:457 slab_free_hook mm/slub.c:1430 [inline] slab_free_freelist_hook mm/slub.c:1457 [inline] slab_free mm/slub.c:3005 [inline] kfree+0xe1/0x270 mm/slub.c:3957 kobject_cleanup lib/kobject.c:662 [inline] kobject_release lib/kobject.c:691 [inline] kref_put include/linux/kref.h:67 [inline] kobject_put+0x146/0x240 lib/kobject.c:708 bus_remove_driver+0x10e/0x220 drivers/base/bus.c:732 driver_unregister+0x6c/0xa0 drivers/base/driver.c:197 usb_register_driver+0x341/0x520 drivers/usb/core/driver.c:980 0xffffffffc1b4817c do_one_initcall+0xfa/0x5ca init/main.c:887 do_init_module+0x204/0x5f6 kernel/module.c:3460 load_module+0x66b2/0x8570 kernel/module.c:3808 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8881f59a6b40 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 48 bytes inside of 256-byte region [ffff8881f59a6b40, ffff8881f59a6c40) The buggy address belongs to the page: page:ffffea0007d66980 count:1 mapcount:0 mapping:ffff8881f6c02e00 index:0x0 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 dead000000000100 dead000000000200 ffff8881f6c02e00 raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff8881f59a6a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881f59a6a80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff8881f59a6b00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
^ ffff8881f59a6b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881f59a6c00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
cpia2_init does not check return value of cpia2_init, if it failed in usb_register_driver, there is already cleanup using driver_unregister. No need call cpia2_usb_cleanup on module exit.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: YueHaibing yuehaibing@huawei.com Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/media/usb/cpia2/cpia2_v4l.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/media/usb/cpia2/cpia2_v4l.c +++ b/drivers/media/usb/cpia2/cpia2_v4l.c @@ -1249,8 +1249,7 @@ static int __init cpia2_init(void) LOG("%s v%s\n", ABOUT, CPIA_VERSION); check_parameters(); - cpia2_usb_init(); - return 0; + return cpia2_usb_init(); }