On Wed, Dec 20, 2017 at 10:17 AM, Stephan Müller <smueller@xxxxxxxxxx> wrote: > Am Mittwoch, 20. Dezember 2017, 08:48:01 CET schrieb syzbot: > > Hi, > >> Hello, >> >> syzkaller hit the following crash on >> 032b4cc8ff84490c4bc7c4ef8c91e6d83a637538 >> 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 >> >> >> ================================================================== >> BUG: KASAN: use-after-free in crypto_aead_free_instance+0xc0/0xd0 >> crypto/aead.c:154 >> Read of size 8 at addr ffff8801c32cf240 by task cryptomgr_test/6646 >> >> CPU: 1 PID: 6646 Comm: cryptomgr_test Not tainted 4.15.0-rc3+ #132 >> 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_load8_noabort+0x14/0x20 mm/kasan/report.c:430 >> crypto_aead_free_instance+0xc0/0xd0 crypto/aead.c:154 >> crypto_free_instance+0x6d/0x100 crypto/algapi.c:77 >> crypto_destroy_instance+0x3c/0x80 crypto/algapi.c:85 >> crypto_alg_put crypto/internal.h:116 [inline] >> crypto_remove_final+0x212/0x370 crypto/algapi.c:331 >> crypto_alg_tested+0x445/0x6f0 crypto/algapi.c:320 >> cryptomgr_test+0x17/0x30 crypto/algboss.c:226 >> kthread+0x37a/0x440 kernel/kthread.c:238 >> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441 >> >> Allocated by task 6641: >> save_stack+0x43/0xd0 mm/kasan/kasan.c:447 >> set_track mm/kasan/kasan.c:459 [inline] >> kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 >> kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3610 >> kmalloc include/linux/slab.h:499 [inline] >> kzalloc include/linux/slab.h:688 [inline] >> pcrypt_create_aead crypto/pcrypt.c:291 [inline] >> pcrypt_create+0x137/0x6c0 crypto/pcrypt.c:346 >> cryptomgr_probe+0x74/0x240 crypto/algboss.c:75 >> kthread+0x37a/0x440 kernel/kthread.c:238 >> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441 >> >> Freed by task 3335: >> save_stack+0x43/0xd0 mm/kasan/kasan.c:447 >> set_track mm/kasan/kasan.c:459 [inline] >> kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 >> __cache_free mm/slab.c:3488 [inline] >> kfree+0xca/0x250 mm/slab.c:3803 >> crypto_larval_destroy+0x110/0x150 crypto/api.c:107 >> crypto_alg_put crypto/internal.h:116 [inline] >> crypto_larval_kill+0x1e8/0x2e0 crypto/api.c:167 >> crypto_alg_mod_lookup+0x178/0x1b0 crypto/api.c:283 >> crypto_find_alg crypto/api.c:501 [inline] >> crypto_alloc_tfm+0xf3/0x2f0 crypto/api.c:534 >> crypto_alloc_aead+0x2c/0x40 crypto/aead.c:342 >> aead_bind+0x70/0x140 crypto/algif_aead.c:482 >> alg_bind+0x1ab/0x440 crypto/af_alg.c:179 >> SYSC_bind+0x1b4/0x3f0 net/socket.c:1454 >> SyS_bind+0x24/0x30 net/socket.c:1440 >> do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] >> do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 >> entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125 >> > This issue vanishes after applying the patch "[PATCH v2] crypto: AF_ALG - > limit mask and type". Hi Stephan, syzbot does not understand arbitrary English prose, it only understands this: > Once a fix for this bug is merged into any tree, reply to this email with: > #syz fix: exact-commit-title Let's tell it about the fix: #syz fix: crypto: AF_ALG - limit mask and type