June 2021 - tor-commits - lists.torproject.org

[tor/release-0.4.5] TROVE-2021-003: Check layer_hint before half-closed end and resolve cells
by nickm＠torproject.org 14 Jun '21

14 Jun '21

commit adb248b6d6e0779719e6b873ee12a1e22fa390f4 Author: David Goulet <dgoulet(a)torproject.org> Date: Thu Jun 3 09:33:21 2021 -0400 TROVE-2021-003: Check layer_hint before half-closed end and resolve cells This issue was reported by Jann Horn part of Google's Project Zero. Jann's one-sentence summary: entry/middle relays can spoof RELAY_END cells on half-closed streams, which can lead to stream confusion between OP and exit. Fixes #40389 --- changes/ticket40389 | 3 +++ src/core/or/relay.c | 25 +++++++++++++++++++++++-- 2 files changed, 26 insertions(+), 2 deletions(-) diff --git a/changes/ticket40389 b/changes/ticket40389 new file mode 100644 index 0000000000..7dcf65b32e --- /dev/null +++ b/changes/ticket40389 @@ -0,0 +1,3 @@ + o Major bugfixes (relay, TROVE): + - Don't allow entry or middle relays to spoof RELAY_END or RELAY_RESOLVED + cell on half-closed streams. Fixes bug 40389; bugfix on 0.3.5.1-alpha. diff --git a/src/core/or/relay.c b/src/core/or/relay.c index f5fc1cfbb3..00353f47a9 100644 --- a/src/core/or/relay.c +++ b/src/core/or/relay.c @@ -1428,6 +1428,25 @@ connection_edge_process_relay_cell_not_open( // return -1; } +/** + * Return true iff our decryption layer_hint is from the last hop + * in a circuit. + */ +static bool +relay_crypt_from_last_hop(origin_circuit_t *circ, crypt_path_t *layer_hint) +{ + tor_assert(circ); + tor_assert(layer_hint); + tor_assert(circ->cpath); + + if (layer_hint != circ->cpath->prev) { + log_fn(LOG_PROTOCOL_WARN, LD_CIRC, + "Got unexpected relay data from intermediate hop"); + return false; + } + return true; +} + /** An incoming relay cell has arrived on circuit circ. If * conn is NULL this is a control cell, else cell is * destined for conn. @@ -1616,7 +1635,8 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ, if (!conn) { if (CIRCUIT_IS_ORIGIN(circ)) { origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ); - if (connection_half_edge_is_valid_end(ocirc->half_streams, + if (relay_crypt_from_last_hop(ocirc, layer_hint) && + connection_half_edge_is_valid_end(ocirc->half_streams, rh.stream_id)) { circuit_read_valid_data(ocirc, rh.length); @@ -1918,7 +1938,8 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ, if (CIRCUIT_IS_ORIGIN(circ)) { origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ); - if (connection_half_edge_is_valid_resolved(ocirc->half_streams, + if (relay_crypt_from_last_hop(ocirc, layer_hint) && + connection_half_edge_is_valid_resolved(ocirc->half_streams, rh.stream_id)) { circuit_read_valid_data(ocirc, rh.length); log_info(domain,

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[tor/release-0.4.5] Backport changelog entries
by nickm＠torproject.org 14 Jun '21

14 Jun '21

commit 5f710eb0871beec55d9d549dac8834d3e756a31c Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Jun 10 13:13:54 2021 -0400 Backport changelog entries --- ChangeLog | 37 +++++++++++++++++++++++++++++++++++++ changes/bug40391 | 9 --------- changes/bug40392 | 4 ---- changes/geoip-2021-06-10 | 3 --- changes/ticket40389 | 3 --- changes/ticket40390 | 8 -------- 6 files changed, 37 insertions(+), 27 deletions(-) diff --git a/ChangeLog b/ChangeLog index 0881e7e500..8bee9f12df 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,12 +1,49 @@ Changes in version 0.4.5.9 - 2021-06-1? BLURB HERE + o Major bugfixes (security, backport from 0.4.6.5): + - Don't allow relays to spoof RELAY_END or RELAY_RESOLVED cell on + half-closed streams. Previously, clients failed to validate which + hop sent these cells: this would allow a relay on a circuit to end + a stream that wasn't actually built with it. Fixes bug 40389; + bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2021- + 003 and CVE-2021-34548. + + o Major bugfixes (security, defense-in-depth, backport from 0.4.6.5): + - Detect more failure conditions from the OpenSSL RNG code. + Previously, we would detect errors from a missing RNG + implementation, but not failures from the RNG code itself. + Fortunately, it appears those failures do not happen in practice + when Tor is using OpenSSL's default RNG implementation. Fixes bug + 40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as + TROVE-2021-004. Reported by Jann Horn at Google's Project Zero. + + o Major bugfixes (security, denial of service, backport from 0.4.6.5): + - Resist a hashtable-based CPU denial-of-service attack against + relays. Previously we used a naive unkeyed hash function to look + up circuits in a circuitmux object. An attacker could exploit this + to construct circuits with chosen circuit IDs, to create + collisions and make the hash table inefficient. Now we use a + SipHash construction here instead. Fixes bug 40391; bugfix on + 0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005 and + CVE-2021-34549. Reported by Jann Horn from Google's Project Zero. + - Fix an out-of-bounds memory access in v3 onion service descriptor + parsing. An attacker could exploit this bug by crafting an onion + service descriptor that would crash any client that tried to visit + it. Fixes bug 40392; bugfix on 0.3.0.1-alpha. This issue is also + tracked as TROVE-2021-006 and CVE-2021-34550. Reported by Sergei + Glazunov from Google's Project Zero. + o Minor features (compatibility, backport from 0.4.6.4-rc): - Remove an assertion function related to TLS renegotiation. It was used nowhere outside the unit tests, and it was breaking compilation with recent alpha releases of OpenSSL 3.0.0. Closes ticket 40399. + o Minor features (geoip data): + - Update the geoip files to match the IPFire Location Database, as + retrieved on 2021/06/10. + o Minor bugfixes (control, sandbox, backport from 0.4.6.4-rc): - Allow the control command SAVECONF to succeed when the seccomp sandbox is enabled, and make SAVECONF keep only one backup file to diff --git a/changes/bug40391 b/changes/bug40391 deleted file mode 100644 index e3c186275f..0000000000 --- a/changes/bug40391 +++ /dev/null @@ -1,9 +0,0 @@ - o Major bugfixes (security): - - Resist a hashtable-based CPU denial-of-service attack against - relays. Previously we used a naive unkeyed hash function to look up - circuits in a circuitmux object. An attacker could exploit this to - construct circuits with chosen circuit IDs in order to try to create - collisions and make the hash table inefficient. Now we use a SipHash - construction for this hash table instead. Fixes bug 40391; bugfix on - 0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005. - Reported by Jann Horn from Google's Project Zero. diff --git a/changes/bug40392 b/changes/bug40392 deleted file mode 100644 index 4dffa50bb2..0000000000 --- a/changes/bug40392 +++ /dev/null @@ -1,4 +0,0 @@ - o Major bugfixes (security, denial of service, onion services): - - Fix an out-of-bounds memory access in v3 descriptor parsing. Fixes bug - 40392; bugfix on 0.3.0.1-alpha. This issue is also tracked as - TROVE-2021-006. Reported by Sergei Glazunov from Google's Project Zero. \ No newline at end of file diff --git a/changes/geoip-2021-06-10 b/changes/geoip-2021-06-10 deleted file mode 100644 index 2b798012c8..0000000000 --- a/changes/geoip-2021-06-10 +++ /dev/null @@ -1,3 +0,0 @@ - o Minor features (geoip data): - - Update the geoip files to match the IPFire Location Database, - as retrieved on 2021/06/10. diff --git a/changes/ticket40389 b/changes/ticket40389 deleted file mode 100644 index 7dcf65b32e..0000000000 --- a/changes/ticket40389 +++ /dev/null @@ -1,3 +0,0 @@ - o Major bugfixes (relay, TROVE): - - Don't allow entry or middle relays to spoof RELAY_END or RELAY_RESOLVED - cell on half-closed streams. Fixes bug 40389; bugfix on 0.3.5.1-alpha. diff --git a/changes/ticket40390 b/changes/ticket40390 deleted file mode 100644 index b56fa4d9da..0000000000 --- a/changes/ticket40390 +++ /dev/null @@ -1,8 +0,0 @@ - o Major bugfixes (security, defense-in-depth): - - Detect a wider variety of failure conditions from the OpenSSL RNG - code. Previously, we would detect errors from a missing RNG - implementation, but not failures from the RNG code itself. - Fortunately, it appears those failures do not happen in practice - when Tor is using OpenSSL's default RNG implementation. - Fixes bug 40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as - TROVE-2021-004. Reported by Jann Horn at Google's Project Zero.

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[tor/release-0.4.5] Merge branch 'maint-0.4.4' into maint-0.4.5
by nickm＠torproject.org 14 Jun '21

14 Jun '21

commit 200e9a55e0737294085080052fbbaba4340d6717 Merge: ae2254e490 0ae9fd62fd Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Jun 10 12:30:29 2021 -0400 Merge branch 'maint-0.4.4' into maint-0.4.5 changes/bug40392 | 4 ++++ src/feature/hs/hs_descriptor.c | 3 ++- 2 files changed, 6 insertions(+), 1 deletion(-)

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[tor/maint-0.4.6] Merge branch 'maint-0.4.4' into maint-0.4.5
by nickm＠torproject.org 14 Jun '21

14 Jun '21

commit d60f8fe98a59ce13809e65de67e53b3dcf6199f0 Merge: c80b98520b 57a41348ee Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Jun 10 08:21:48 2021 -0400 Merge branch 'maint-0.4.4' into maint-0.4.5 changes/geoip-2021-06-10 | 3 + src/config/geoip | 4764 +++++++++++++++++++++++++++------------------- src/config/geoip6 | 2826 ++++++++++++++++----------- 3 files changed, 4536 insertions(+), 3057 deletions(-)

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[tor/maint-0.4.6] Merge branch 'maint-0.3.5' into maint-0.4.4
by nickm＠torproject.org 14 Jun '21

14 Jun '21

commit 57a41348eee001809cd77326ca35406888b5a64b Merge: 1956f63d6b 520d5c108f Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Jun 10 08:21:47 2021 -0400 Merge branch 'maint-0.3.5' into maint-0.4.4 changes/geoip-2021-06-10 | 3 + src/config/geoip | 4764 +++++++++++++++++++++++++++------------------- src/config/geoip6 | 2826 ++++++++++++++++----------- 3 files changed, 4536 insertions(+), 3057 deletions(-)

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[tor/maint-0.4.6] Merge branch 'maint-0.4.5' into maint-0.4.6
by nickm＠torproject.org 14 Jun '21

14 Jun '21

commit cb3821966430abc51d81cb01bd32fc956f0c8125 Merge: b3fe9d5162 d60f8fe98a Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Jun 10 08:21:48 2021 -0400 Merge branch 'maint-0.4.5' into maint-0.4.6 changes/geoip-2021-06-10 | 3 + src/config/geoip | 4764 +++++++++++++++++++++++++++------------------- src/config/geoip6 | 2826 ++++++++++++++++----------- 3 files changed, 4536 insertions(+), 3057 deletions(-)

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[tor/maint-0.4.6] Merge branch 'bug40390_035_squashed' into maint-0.3.5
by nickm＠torproject.org 14 Jun '21

14 Jun '21

commit 7fdfc2ea5470c572a113321e19cdb5144b10cdd8 Merge: 520d5c108f c0aa9e0a1b Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Jun 10 08:34:25 2021 -0400 Merge branch 'bug40390_035_squashed' into maint-0.3.5 changes/ticket40390 | 8 ++++++++ src/lib/crypt_ops/crypto_rand.c | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-)

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[tor/maint-0.4.6] Merge branch 'maint-0.3.5' into maint-0.4.4
by nickm＠torproject.org 14 Jun '21

14 Jun '21

commit 7c19a4d924120f42c224ea357b388b73d05c2d89 Merge: 57a41348ee 7fdfc2ea54 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Jun 10 08:37:26 2021 -0400 Merge branch 'maint-0.3.5' into maint-0.4.4 changes/ticket40390 | 8 ++++++++ src/lib/crypt_ops/crypto_rand.c | 4 ++-- 2 files changed, 10 insertions(+), 2 deletions(-)

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[tor/maint-0.4.6] Assert on _all_ failures from RAND_bytes().
by nickm＠torproject.org 14 Jun '21

14 Jun '21

commit c0aa9e0a1b1633d3b221199d516294e14a5db9c6 Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon May 17 08:50:01 2021 -0400 Assert on _all_ failures from RAND_bytes(). Previously, we would detect errors from a missing RNG implementation, but not failures from the RNG code itself. Fortunately, it appears those failures do not happen in practice when Tor is using OpenSSL's default RNG implementation. Fixes bug 40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as TROVE-2021-004. Reported by Jann Horn at Google's Project Zero. --- changes/ticket40390 | 8 ++++++++ src/lib/crypt_ops/crypto_rand.c | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/changes/ticket40390 b/changes/ticket40390 new file mode 100644 index 0000000000..b56fa4d9da --- /dev/null +++ b/changes/ticket40390 @@ -0,0 +1,8 @@ + o Major bugfixes (security, defense-in-depth): + - Detect a wider variety of failure conditions from the OpenSSL RNG + code. Previously, we would detect errors from a missing RNG + implementation, but not failures from the RNG code itself. + Fortunately, it appears those failures do not happen in practice + when Tor is using OpenSSL's default RNG implementation. + Fixes bug 40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as + TROVE-2021-004. Reported by Jann Horn at Google's Project Zero. diff --git a/src/lib/crypt_ops/crypto_rand.c b/src/lib/crypt_ops/crypto_rand.c index 915fe0870d..206929d6b3 100644 --- a/src/lib/crypt_ops/crypto_rand.c +++ b/src/lib/crypt_ops/crypto_rand.c @@ -525,7 +525,7 @@ crypto_rand_unmocked(char *to, size_t n) /* We consider a PRNG failure non-survivable. Let's assert so that we get a * stack trace about where it happened. */ - tor_assert(r >= 0); + tor_assert(r == 1); #endif }

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[tor/maint-0.4.6] Merge branch 'maint-0.4.4' into maint-0.4.5
by nickm＠torproject.org 14 Jun '21

14 Jun '21

commit e2d01aac9e2f45f2c8f0de057f3104d6cfcdaa80 Merge: d60f8fe98a 7c19a4d924 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Jun 10 08:37:34 2021 -0400 Merge branch 'maint-0.4.4' into maint-0.4.5 changes/ticket40390 | 8 ++++++++ src/lib/crypt_ops/crypto_rand.c | 4 ++-- 2 files changed, 10 insertions(+), 2 deletions(-)

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