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

[tor/maint-0.4.4] Merge branch 'maint-0.3.5' into maint-0.4.4
by nickm＠torproject.org 16 Mar '21

16 Mar '21

commit b9f65390089817a74bf20d93e93a15b41a970f79 Merge: fb2c889a38 f46f4562cf Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon Mar 15 08:52:28 2021 -0400 Merge branch 'maint-0.3.5' into maint-0.4.4 changes/ticket40286_minimal | 5 +++++ src/feature/dirparse/unparseable.c | 6 ++++++ 2 files changed, 11 insertions(+)

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[tor/maint-0.4.4] Fix detection of point to insert signatures on a pending consensus.
by nickm＠torproject.org 16 Mar '21

16 Mar '21

commit 890ae4fb1adfa13e37aaf5261e089e8c195a75cf Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Mar 3 15:14:31 2021 -0500 Fix detection of point to insert signatures on a pending consensus. We were looking for the first instance of "directory-signature " when instead the correct behavior is to look for the first instance of "directory-signature " at the start of a line. Unfortunately, this can be exploited as to crash authorities while they're voting. Fixes #40316; bugfix on 0.2.2.4-alpha. This is TROVE-2021-002, also tracked as CVE-2021-28090. --- changes/bug40316 | 5 +++++ src/feature/dirauth/dirvote.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/changes/bug40316 b/changes/bug40316 new file mode 100644 index 0000000000..cd275b5c9c --- /dev/null +++ b/changes/bug40316 @@ -0,0 +1,5 @@ + o Major bugfixes (security, denial of service): + - Fix a bug in appending detached signatures to a pending consensus + document that could be used to crash a directory authority. + Fixes bug 40316; bugfix on 0.2.2.6-alpha. Tracked as + TROVE-2021-002 and CVE-2021-28090. diff --git a/src/feature/dirauth/dirvote.c b/src/feature/dirauth/dirvote.c index af8b3dc207..9e01cee42a 100644 --- a/src/feature/dirauth/dirvote.c +++ b/src/feature/dirauth/dirvote.c @@ -3520,7 +3520,7 @@ dirvote_add_signatures_to_pending_consensus( strlen(pc->body) + strlen(new_signatures) + 1; pc->body = tor_realloc(pc->body, new_consensus_len); dst_end = pc->body + new_consensus_len; - dst = strstr(pc->body, "directory-signature "); + dst = (char *) find_str_at_start_of_line(pc->body, "directory-signature "); tor_assert(dst); strlcpy(dst, new_signatures, dst_end-dst);

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[tor/maint-0.4.5] Merge branch 'maint-0.4.4' into maint-0.4.5
by nickm＠torproject.org 16 Mar '21

16 Mar '21

commit 7c5a67ccd983bb028d21a5e8aa48b4cd9d6a8a1c Merge: be17a5a3cf b9f6539008 Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon Mar 15 08:52:29 2021 -0400 Merge branch 'maint-0.4.4' into maint-0.4.5 changes/ticket40286_minimal | 5 +++++ src/feature/dirparse/unparseable.c | 6 ++++++ 2 files changed, 11 insertions(+)

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[tor/maint-0.4.5] Fix detection of point to insert signatures on a pending consensus.
by nickm＠torproject.org 16 Mar '21

16 Mar '21

commit 890ae4fb1adfa13e37aaf5261e089e8c195a75cf Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Mar 3 15:14:31 2021 -0500 Fix detection of point to insert signatures on a pending consensus. We were looking for the first instance of "directory-signature " when instead the correct behavior is to look for the first instance of "directory-signature " at the start of a line. Unfortunately, this can be exploited as to crash authorities while they're voting. Fixes #40316; bugfix on 0.2.2.4-alpha. This is TROVE-2021-002, also tracked as CVE-2021-28090. --- changes/bug40316 | 5 +++++ src/feature/dirauth/dirvote.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/changes/bug40316 b/changes/bug40316 new file mode 100644 index 0000000000..cd275b5c9c --- /dev/null +++ b/changes/bug40316 @@ -0,0 +1,5 @@ + o Major bugfixes (security, denial of service): + - Fix a bug in appending detached signatures to a pending consensus + document that could be used to crash a directory authority. + Fixes bug 40316; bugfix on 0.2.2.6-alpha. Tracked as + TROVE-2021-002 and CVE-2021-28090. diff --git a/src/feature/dirauth/dirvote.c b/src/feature/dirauth/dirvote.c index af8b3dc207..9e01cee42a 100644 --- a/src/feature/dirauth/dirvote.c +++ b/src/feature/dirauth/dirvote.c @@ -3520,7 +3520,7 @@ dirvote_add_signatures_to_pending_consensus( strlen(pc->body) + strlen(new_signatures) + 1; pc->body = tor_realloc(pc->body, new_consensus_len); dst_end = pc->body + new_consensus_len; - dst = strstr(pc->body, "directory-signature "); + dst = (char *) find_str_at_start_of_line(pc->body, "directory-signature "); tor_assert(dst); strlcpy(dst, new_signatures, dst_end-dst);

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[tor/maint-0.4.5] Merge branch 'maint-0.4.4' into maint-0.4.5
by nickm＠torproject.org 16 Mar '21

16 Mar '21

commit a6533af9e8d90fda13180064e98b49ac3c3cdf86 Merge: 7c5a67ccd9 2eb900f7e2 Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon Mar 15 08:54:00 2021 -0400 Merge branch 'maint-0.4.4' into maint-0.4.5 changes/ticket40286_minimal | 7 ++++--- src/feature/dirparse/unparseable.c | 7 +++++-- 2 files changed, 9 insertions(+), 5 deletions(-)

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[tor/maint-0.4.5] Clarify new intended strategy with TROVE-2021-001
by nickm＠torproject.org 16 Mar '21

16 Mar '21

commit efca9ce41c96bb0044f504ced36a2734b1689ee2 Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon Mar 15 08:53:36 2021 -0400 Clarify new intended strategy with TROVE-2021-001 We're going to disable this feature in all versions for now. --- changes/ticket40286_minimal | 7 ++++--- src/feature/dirparse/unparseable.c | 7 +++++-- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/changes/ticket40286_minimal b/changes/ticket40286_minimal index b8669debaa..6a04ca79eb 100644 --- a/changes/ticket40286_minimal +++ b/changes/ticket40286_minimal @@ -1,5 +1,6 @@ - o Major bugfixes (denial of service): + o Major bugfixes (security, denial of service): - Disable the dump_desc() function that we used to dump unparseable information to disk. It was called incorrectly in several places, - in a way that could lead to excessive CPU usage. - Fixes bug 40286; bugfix on 0.2.2.1-alpha. + in a way that could lead to excessive CPU usage. Fixes bug 40286; + bugfix on 0.2.2.1-alpha. This bug is also tracked as + TROVE-2021-001 and CVE-2021-28089. diff --git a/src/feature/dirparse/unparseable.c b/src/feature/dirparse/unparseable.c index a547335452..1d623fe701 100644 --- a/src/feature/dirparse/unparseable.c +++ b/src/feature/dirparse/unparseable.c @@ -493,8 +493,11 @@ dump_desc,(const char *desc, const char *type)) tor_assert(desc); tor_assert(type); #ifndef TOR_UNIT_TESTS - /* On older versions of Tor we are disabling this function, since it - * can be called with strings that are far too long. */ + /* For now, we are disabling this function, since it can be called with + * strings that are far too long. We can turn it back on if we fix it + * someday, but we'd need to give it a length argument. A likelier + * resolution here is simply to remove this module entirely. See tor#40286 + * for background. */ if (1) return; #endif

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[tor/maint-0.4.4] Merge branch 'bug40286_disable_min_035' into maint-0.3.5
by nickm＠torproject.org 16 Mar '21

16 Mar '21

commit f46f4562cf6f47fe6c00752f61b04dc18a454253 Merge: 1a0b5fd569 ede88c374c Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon Mar 15 08:41:03 2021 -0400 Merge branch 'bug40286_disable_min_035' into maint-0.3.5 changes/ticket40286_minimal | 5 +++++ src/feature/dirparse/unparseable.c | 6 ++++++ 2 files changed, 11 insertions(+)

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[tor/maint-0.4.4] Merge branch 'maint-0.3.5' into maint-0.4.4
by nickm＠torproject.org 16 Mar '21

16 Mar '21

commit 5ec579610ace4d3e4f0a6432b26e1e968beccf36 Merge: 2eb900f7e2 f078aab71e Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon Mar 15 09:01:59 2021 -0400 Merge branch 'maint-0.3.5' into maint-0.4.4 changes/bug40316 | 5 +++++ src/feature/dirauth/dirvote.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-)

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[tor/maint-0.4.4] Merge branch 'bug40316_035_v2' into maint-0.3.5
by nickm＠torproject.org 16 Mar '21

16 Mar '21

commit f078aab71ef56e1942caec5f27e0f336f2a7c7d1 Merge: efca9ce41c 890ae4fb1a Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon Mar 15 08:58:54 2021 -0400 Merge branch 'bug40316_035_v2' into maint-0.3.5 changes/bug40316 | 5 +++++ src/feature/dirauth/dirvote.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-)

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[tor/maint-0.4.5] Disable the dump_desc() function.
by nickm＠torproject.org 16 Mar '21

16 Mar '21

commit ede88c374cd61e1e362422718625707a770cffff Author: Nick Mathewson <nickm(a)torproject.org> Date: Fri Feb 19 12:31:19 2021 -0500 Disable the dump_desc() function. It can be called with strings that should have been length-delimited, but which in fact are not. This can cause a CPU-DoS bug or, in a worse case, a crash. Since this function isn't essential, the best solution for older Tors is to just turn it off. Fixes bug 40286; bugfix on 0.2.2.1-alpha when dump_desc() was introduced. --- changes/ticket40286_minimal | 5 +++++ src/feature/dirparse/unparseable.c | 6 ++++++ 2 files changed, 11 insertions(+) diff --git a/changes/ticket40286_minimal b/changes/ticket40286_minimal new file mode 100644 index 0000000000..b8669debaa --- /dev/null +++ b/changes/ticket40286_minimal @@ -0,0 +1,5 @@ + o Major bugfixes (denial of service): + - Disable the dump_desc() function that we used to dump unparseable + information to disk. It was called incorrectly in several places, + in a way that could lead to excessive CPU usage. + Fixes bug 40286; bugfix on 0.2.2.1-alpha. diff --git a/src/feature/dirparse/unparseable.c b/src/feature/dirparse/unparseable.c index 941b5a1f6d..a547335452 100644 --- a/src/feature/dirparse/unparseable.c +++ b/src/feature/dirparse/unparseable.c @@ -492,6 +492,12 @@ dump_desc,(const char *desc, const char *type)) { tor_assert(desc); tor_assert(type); +#ifndef TOR_UNIT_TESTS + /* On older versions of Tor we are disabling this function, since it + * can be called with strings that are far too long. */ + if (1) + return; +#endif size_t len; /* The SHA256 of the string */ uint8_t digest_sha256[DIGEST256_LEN];

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