Hello, On commit a88164345b81292b55a8d4829fdd35c8d611cd7d (Dec 23) + crypto: algif_skcipher - Use new skcipher interface + crypto: algif_skcipher - Require setkey before accept(2) The following program triggers use-after-free in rng_recvmsg: // autogenerated by syzkaller (http://github.com/google/syzkaller) #include <unistd.h> #include <sys/syscall.h> #include <string.h> #include <stdint.h> #include <pthread.h> #ifndef SYS_memfd_create #define SYS_memfd_create 319 #endif long r[13]; void *thr(void *arg) { switch ((long)arg) { case 0: r[0] = syscall(SYS_mmap, 0x20000000ul, 0x11000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); break; case 1: r[1] = syscall(SYS_socket, 0x26ul, 0x5ul, 0x0ul, 0, 0, 0); break; case 2: *(uint16_t*)0x20003000 = (uint16_t)0x26; memcpy((void*)0x20003002, "\x72\x6e\x67\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 14); *(uint32_t*)0x20003010 = (uint32_t)0x8; *(uint32_t*)0x20003014 = (uint32_t)0x800; memcpy((void*)0x20003018, "\x73\x74\x64\x72\x6e\x67\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 64); r[7] = syscall(SYS_bind, r[1], 0x20003000ul, 0x58ul, 0, 0, 0); break; case 3: memcpy((void*)0x20003ff0, "\x26\x73\x79\x73\x74\x65\x6d\x73\x65\x63\x75\x72\x69\x74\x79\x00", 16); r[9] = syscall(SYS_memfd_create, 0x20003ff0ul, 0x2ul, 0, 0, 0, 0); break; case 4: r[10] = syscall(SYS_ioctl, r[9], 0x540bul, 0x4ul, 0, 0, 0); break; case 5: r[11] = syscall(SYS_accept, r[1], 0x0ul, 0x2000affcul, 0, 0, 0); break; case 6: r[12] = syscall(SYS_read, r[11], 0x200102a3ul, 0x54ul, 0, 0, 0); break; } return 0; } int main() { long i; pthread_t th[7]; memset(r, -1, sizeof(r)); for (i = 0; i < 7; i++) { pthread_create(&th[i], 0, thr, (void*)i); usleep(10000); } for (i = 0; i < 7; i++) { pthread_create(&th[i], 0, thr, (void*)i); if (i%2==0) usleep(10000); } usleep(100000); return 0; } ================================================================== BUG: KASAN: use-after-free in rng_recvmsg+0x20f/0x230 at addr ffff880061c4d758 Read of size 8 by task a.out/8875 ============================================================================= BUG kmalloc-512 (Not tainted): kasan: bad access detected ----------------------------------------------------------------------------- INFO: Allocated in crypto_create_tfm+0x7e/0x240 age=97 cpu=2 pid=8833 [< inline >] kmalloc include/linux/slab.h:463 [< inline >] kzalloc include/linux/slab.h:602 [< none >] crypto_create_tfm+0x7e/0x240 crypto/api.c:470 [< none >] crypto_alloc_tfm+0x13c/0x370 crypto/api.c:555 [< none >] crypto_alloc_rng+0x2c/0x40 crypto/rng.c:120 [< none >] rng_bind+0x25/0x30 crypto/algif_rng.c:119 [< none >] alg_bind+0x18e/0x3a0 crypto/af_alg.c:155 [< none >] SYSC_bind+0x1ea/0x250 net/socket.c:1376 [< none >] SyS_bind+0x24/0x30 net/socket.c:1362 [< none >] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 INFO: Freed in kzfree+0x28/0x30 age=46 cpu=1 pid=8859 [< none >] kfree+0x26a/0x290 mm/slub.c:3662 [< none >] kzfree+0x28/0x30 mm/slab_common.c:1270 [< none >] crypto_destroy_tfm+0xcb/0x190 crypto/api.c:596 [< inline >] crypto_free_rng include/crypto/rng.h:122 [< none >] rng_release+0x18/0x20 crypto/algif_rng.c:124 [< inline >] alg_do_release crypto/af_alg.c:116 [< none >] alg_bind+0x246/0x3a0 crypto/af_alg.c:170 [< none >] SYSC_bind+0x1ea/0x250 net/socket.c:1376 [< none >] SyS_bind+0x24/0x30 net/socket.c:1362 [< none >] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 INFO: Slab 0xffffea0001871300 objects=16 used=14 fp=0xffff880061c4e670 flags=0x5fffc0000004080 INFO: Object 0xffff880061c4d710 @offset=5904 fp=0x (null) CPU: 1 PID: 8875 Comm: a.out Tainted: G B 4.4.0-rc6+ #178 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 00000000ffffffff ffff880036edf9a0 ffffffff8289db7d ffff88003e804f00 ffff880061c4d710 ffff880061c4c000 ffff880036edf9d0 ffffffff816c9064 ffff88003e804f00 ffffea0001871300 ffff880061c4d710 ffff880036edfaf0 Call Trace: [<ffffffff816d25de>] __asan_report_load8_noabort+0x3e/0x40 mm/kasan/report.c:295 [< inline >] crypto_rng_get_bytes include/crypto/rng.h:112 [<ffffffff827e634f>] rng_recvmsg+0x20f/0x230 crypto/algif_rng.c:85 [< inline >] sock_recvmsg_nosec net/socket.c:712 [<ffffffff84b5bcfd>] sock_recvmsg+0x9d/0xb0 net/socket.c:720 [<ffffffff84b5bf5d>] sock_read_iter+0x24d/0x360 net/socket.c:797 [< inline >] new_sync_read fs/read_write.c:422 [<ffffffff81712b0d>] __vfs_read+0x2fd/0x460 fs/read_write.c:434 [<ffffffff81714c76>] vfs_read+0x106/0x310 fs/read_write.c:454 [< inline >] SYSC_read fs/read_write.c:569 [<ffffffff81717a21>] SyS_read+0x111/0x220 fs/read_write.c:562 [<ffffffff85c8ecf6>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 ================================================================== Another report on a different program, but with a similar cause: ================================================================== BUG: KASAN: use-after-free in hash_sock_destruct+0x1a7/0x1d0 at addr ffff88003abce248 Read of size 8 by task syz-executor/21732 ============================================================================= BUG kmalloc-192 (Tainted: G B D ): kasan: bad access detected ----------------------------------------------------------------------------- INFO: Allocated in crypto_create_tfm+0x7e/0x240 age=28 cpu=1 pid=21732 [< inline >] kmalloc include/linux/slab.h:463 [< inline >] kzalloc include/linux/slab.h:602 [< none >] crypto_create_tfm+0x7e/0x240 crypto/api.c:470 [< none >] crypto_alloc_tfm+0x13c/0x370 crypto/api.c:555 [< none >] crypto_alloc_ahash+0x2c/0x40 crypto/ahash.c:538 [< none >] hash_bind+0x25/0x30 crypto/algif_hash.c:240 [< none >] alg_bind+0x18e/0x3a0 crypto/af_alg.c:155 [< none >] SYSC_bind+0x1ea/0x250 net/socket.c:1376 [< none >] SyS_bind+0x24/0x30 net/socket.c:1362 [< none >] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 INFO: Freed in kzfree+0x28/0x30 age=32 cpu=0 pid=21733 [< none >] kfree+0x26a/0x290 mm/slub.c:3662 [< none >] kzfree+0x28/0x30 mm/slab_common.c:1270 [< none >] crypto_destroy_tfm+0xcb/0x190 crypto/api.c:596 [< inline >] crypto_free_ahash include/crypto/hash.h:258 [< none >] hash_release+0x19/0x20 crypto/algif_hash.c:245 [< inline >] alg_do_release crypto/af_alg.c:116 [< none >] alg_bind+0x246/0x3a0 crypto/af_alg.c:170 [< none >] SYSC_bind+0x1ea/0x250 net/socket.c:1376 [< none >] SyS_bind+0x24/0x30 net/socket.c:1362 [< none >] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 INFO: Slab 0xffffea0000eaf300 objects=24 used=15 fp=0xffff88003abce1b8 flags=0x1fffc0000004080 INFO: Object 0xffff88003abce1b8 @offset=8632 fp=0xffff88003abce6e8 CPU: 1 PID: 21732 Comm: syz-executor Tainted: G B D 4.4.0-rc6+ #178 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 00000000ffffffff ffff88006d4977d8 ffffffff8289db7d ffff88003e804c00 ffff88003abce1b8 ffff88003abcc000 ffff88006d497808 ffffffff816c9064 ffff88003e804c00 ffffea0000eaf300 ffff88003abce1b8 0000000000000000 Call Trace: [<ffffffff816d25de>] __asan_report_load8_noabort+0x3e/0x40 mm/kasan/report.c:295 [< inline >] crypto_ahash_digestsize include/crypto/hash.h:290 [<ffffffff827dff87>] hash_sock_destruct+0x1a7/0x1d0 crypto/algif_hash.c:259 [<ffffffff84b6f46a>] sk_destruct+0x4a/0x490 net/core/sock.c:1447 [<ffffffff84b6f907>] __sk_free+0x57/0x200 net/core/sock.c:1475 [<ffffffff84b6fae0>] sk_free+0x30/0x40 net/core/sock.c:1486 [< inline >] sock_put include/net/sock.h:1627 [<ffffffff827dcf5b>] af_alg_release+0x5b/0x70 crypto/af_alg.c:123 [<ffffffff84b5944d>] sock_release+0x8d/0x1d0 net/socket.c:571 [<ffffffff84b595a6>] sock_close+0x16/0x20 net/socket.c:1022 [<ffffffff81719a73>] __fput+0x233/0x780 fs/file_table.c:208 [<ffffffff8171a045>] ____fput+0x15/0x20 fs/file_table.c:244 [<ffffffff8134679b>] task_work_run+0x16b/0x200 kernel/task_work.c:115 [< inline >] exit_task_work include/linux/task_work.h:21 [<ffffffff812f4d3b>] do_exit+0x8bb/0x2b20 kernel/exit.c:750 [<ffffffff812f7118>] do_group_exit+0x108/0x320 kernel/exit.c:880 [<ffffffff813196c4>] get_signal+0x5e4/0x1500 kernel/signal.c:2307 [<ffffffff811507a3>] do_signal+0x83/0x1c90 arch/x86/kernel/signal.c:712 [<ffffffff81003901>] exit_to_usermode_loop+0xf1/0x1a0 arch/x86/entry/common.c:247 [< inline >] prepare_exit_to_usermode arch/x86/entry/common.c:282 [<ffffffff8100631f>] syscall_return_slowpath+0x19f/0x210 arch/x86/entry/common.c:344 [<ffffffff85c8ee62>] int_ret_from_sys_call+0x25/0x9f arch/x86/entry/entry_64.S:281 ================================================================== -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
