random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) ================================================================== BUG: KASAN: slab-out-of-bounds in fscache_set_key fs/fscache/cookie.c:120 [inline] BUG: KASAN: slab-out-of-bounds in fscache_alloc_cookie+0x740/0x800 fs/fscache/cookie.c:171 Read of size 4 at addr ffff8801cde475b4 by task syz-executor803/4465 CPU: 1 PID: 4465 Comm: syz-executor803 Not tainted 4.18.0-rc3-next-20180709+ #2 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+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 fscache_set_key fs/fscache/cookie.c:120 [inline] fscache_alloc_cookie+0x740/0x800 fs/fscache/cookie.c:171 __fscache_acquire_cookie+0x230/0xb00 fs/fscache/cookie.c:303 fscache_acquire_cookie include/linux/fscache.h:338 [inline] v9fs_cache_session_get_cookie+0xc4/0x270 fs/9p/cache.c:73 v9fs_session_init+0x1013/0x1a80 fs/9p/v9fs.c:464 v9fs_mount+0x7c/0x900 fs/9p/vfs_super.c:135 legacy_get_tree+0x118/0x440 fs/fs_context.c:659 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1751 do_new_mount fs/namespace.c:2567 [inline] do_mount+0x6c1/0x1fb0 fs/namespace.c:2889 ksys_mount+0x12d/0x140 fs/namespace.c:3105 __do_sys_mount fs/namespace.c:3119 [inline] __se_sys_mount fs/namespace.c:3116 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3116 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x440309 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffc98180878 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 6761746568636163 RCX: 0000000000440309 RDX: 00000000200002c0 RSI: 0000000020000280 RDI: 0000000000000000 RBP: 00000000006ca018 R08: 0000000020000340 R09: 00000000004002c8 R10: 0000000000800000 R11: 0000000000000206 R12: 0000000000401b90 R13: 0000000000401c20 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4465: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x14e/0x760 mm/slab.c:3727 kmalloc include/linux/slab.h:518 [inline] kzalloc include/linux/slab.h:707 [inline] fscache_set_key fs/fscache/cookie.c:101 [inline] fscache_alloc_cookie+0x698/0x800 fs/fscache/cookie.c:171 __fscache_acquire_cookie+0x230/0xb00 fs/fscache/cookie.c:303 fscache_acquire_cookie include/linux/fscache.h:338 [inline] v9fs_cache_session_get_cookie+0xc4/0x270 fs/9p/cache.c:73 v9fs_session_init+0x1013/0x1a80 fs/9p/v9fs.c:464 v9fs_mount+0x7c/0x900 fs/9p/vfs_super.c:135 legacy_get_tree+0x118/0x440 fs/fs_context.c:659 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1751 do_new_mount fs/namespace.c:2567 [inline] do_mount+0x6c1/0x1fb0 fs/namespace.c:2889 ksys_mount+0x12d/0x140 fs/namespace.c:3105 __do_sys_mount fs/namespace.c:3119 [inline] __se_sys_mount fs/namespace.c:3116 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3116 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 1: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 kobject_uevent_env+0x275/0x1110 lib/kobject_uevent.c:619 kobject_uevent+0x1f/0x30 lib/kobject_uevent.c:636 device_add+0x95d/0x16f0 drivers/base/core.c:1904 device_create_groups_vargs+0x1ff/0x270 drivers/base/core.c:2501 device_create_vargs drivers/base/core.c:2541 [inline] device_create+0xdb/0x110 drivers/base/core.c:2577 sound_insert_unit.constprop.2+0x695/0x870 sound/sound_core.c:287 register_sound_special_device+0xf4/0x2e0 sound/sound_core.c:415 snd_register_oss_device+0x2a4/0x4e0 sound/core/sound_oss.c:138 register_device sound/core/seq/oss/seq_oss.c:233 [inline] alsa_seq_oss_init+0x32/0x26c sound/core/seq/oss/seq_oss.c:83 do_one_initcall+0x127/0x913 init/main.c:884 do_initcall_level init/main.c:952 [inline] do_initcalls init/main.c:960 [inline] do_basic_setup init/main.c:978 [inline] kernel_init_freeable+0x49b/0x58e init/main.c:1135 kernel_init+0x11/0x1b3 init/main.c:1061 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 The buggy address belongs to the object at ffff8801cde47580 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 52 bytes inside of 64-byte region [ffff8801cde47580, ffff8801cde475c0) The buggy address belongs to the page: page:ffffea00073791c0 count:1 mapcount:0 mapping:ffff8801da800340 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0007361408 ffff8801da801348 ffff8801da800340 raw: 0000000000000000 ffff8801cde47000 0000000100000020 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cde47480: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff8801cde47500: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc >ffff8801cde47580: 00 00 00 00 00 00 07 fc fc fc fc fc fc fc fc fc ^ ffff8801cde47600: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff8801cde47680: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ==================================================================