/* * netsniff-ng - the packet sniffing beast * Copyright 2011 - 2013 Daniel Borkmann. * Subject to the GPL, version 2. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "built_in.h" #include "xmalloc.h" #include "curve.h" #include "ioops.h" #include "rnd.h" #include "die.h" #include "str.h" #include "curvetun.h" #include "locking.h" #include "crypto.h" #include "config.h" static void curve25519_init(struct curve25519_struct *curve) { curve->enc_size = curve->dec_size = TUNBUFF_SIZ; curve->enc = xmalloc_aligned(curve->enc_size, 16); curve->dec = xmalloc_aligned(curve->dec_size, 16); spinlock_init(&curve->enc_lock); spinlock_init(&curve->dec_lock); } static void curve25519_destroy(struct curve25519_struct *curve) { spinlock_destroy(&curve->enc_lock); spinlock_destroy(&curve->dec_lock); xzfree(curve->enc, curve->enc_size); xzfree(curve->dec, curve->dec_size); } struct curve25519_struct *curve25519_tfm_alloc(void) { struct curve25519_struct *tfm; tfm = xzmalloc_aligned(sizeof(*tfm), 16); curve25519_init(tfm); return tfm; } void curve25519_tfm_free(struct curve25519_struct *tfm) { curve25519_destroy(tfm); xzfree(tfm, sizeof(*tfm)); } void curve25519_tfm_free_void(void *tfm) { curve25519_tfm_free(tfm); } void curve25519_proto_init(struct curve25519_proto *proto, unsigned char *pubkey_remote, size_t len) { int result; char file[128]; struct passwd *pw = getpwuid(getuid()); unsigned char secretkey_own[crypto_box_sec_key_size]; unsigned char publickey_own[crypto_box_pub_key_size]; fmemset(secretkey_own, 0, sizeof(secretkey_own)); fmemset(publickey_own, 0, sizeof(publickey_own)); if (unlikely(!pubkey_remote || len != sizeof(publickey_own))) panic("Invalid argument on curve25519_proto_init!\n"); slprintf(file, sizeof(file), "%s/%s", pw->pw_dir, FILE_PRIVKEY); read_blob_or_die(file, secretkey_own, sizeof(secretkey_own)); crypto_scalarmult_curve25519_base(publickey_own, secretkey_own); result = crypto_verify_32(publickey_own, pubkey_remote); if (result == 0) panic("Remote end has same public key as you have!\n"); crypto_box_beforenm(proto->key, pubkey_remote, secretkey_own); fmemset(proto->enonce, 0, sizeof(proto->enonce)); fmemset(proto->dnonce, 0, sizeof(proto->dnonce)); xmemset(secretkey_own, 0, sizeof(secretkey_own)); xmemset(publickey_own, 0, sizeof(publickey_own)); } ssize_t curve25519_encode(struct curve25519_struct *curve, struct curve25519_proto *proto, unsigned char *plaintext, size_t size, unsigned char **ciphertext) { int ret, i; ssize_t done = size; struct taia packet_taia; spinlock_lock(&curve->enc_lock); if (unlikely(size > curve->enc_size)) { done = -ENOMEM; goto out; } taia_now(&packet_taia); taia_pack(NONCE_EDN_OFFSET(proto->enonce), &packet_taia); fmemset(curve->enc, 0, curve->enc_size); ret = crypto_box_afternm(curve->enc, plaintext, size, proto->enonce, proto->key); if (unlikely(ret)) { done = -EIO; goto out; } fmemcpy(NONCE_PKT_OFFSET(curve->enc), NONCE_EDN_OFFSET(proto->enonce), NONCE_LENGTH); for (i = 0; i < NONCE_RND_LENGTH; ++i) curve->enc[i] = (uint8_t) secrand(); (*ciphertext) = curve->enc; out: spinlock_unlock(&curve->enc_lock); return done; } ssize_t curve25519_decode(struct curve25519_struct *curve, struct curve25519_proto *proto, unsigned char *ciphertext, size_t size, unsigned char **plaintext, struct taia *arrival_taia) { int ret; ssize_t done = size; struct taia packet_taia, tmp_taia; spinlock_lock(&curve->dec_lock); if (unlikely(size > curve->dec_size || size < NONCE_ALL_LENGTH)) { done = size < NONCE_ALL_LENGTH ? 0 : -ENOMEM; goto out; } if (arrival_taia == NULL) { taia_now(&tmp_taia); arrival_taia = &tmp_taia; } taia_unpack(NONCE_PKT_OFFSET(ciphertext), &packet_taia); if (taia_looks_good(arrival_taia, &packet_taia) == 0) { done = 0; goto out; } fmemcpy(NONCE_EDN_OFFSET(proto->dnonce), NONCE_PKT_OFFSET(ciphertext), NONCE_LENGTH); fmemset(curve->dec, 0, curve->dec_size); ret = crypto_box_open_afternm(curve->dec, ciphertext, size, proto->dnonce, proto->key); if (unlikely(ret)) { done = -EIO; goto out; } (*plaintext) = curve->dec; out: spinlock_unlock(&curve->dec_lock); return done; } int curve25519_pubkey_hexparse_32(unsigned char *bin, size_t blen, const char *ascii, size_t alen) { int ret = sscanf(ascii, "%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:" "%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:" "%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:" "%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx", &bin[0], &bin[1], &bin[2], &bin[3], &bin[4], &bin[5], &bin[6], &bin[7], &bin[8], &bin[9], &bin[10], &bin[11], &bin[12], &bin[13], &bin[14], &bin[15], &bin[16], &bin[17], &bin[18], &bin[19], &bin[20], &bin[21], &bin[22], &bin[23], &bin[24], &bin[25], &bin[26], &bin[27], &bin[28], &bin[29], &bin[30], &bin[31]); return ret == 32; } 09e0144dc3341'>patch) tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /drivers/usb/host/ehci.h parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'drivers/usb/host/ehci.h')