commit 9a06282546418b2e9d21559d4853bcf124b953f4 Author: Nick Mathewson nickm@torproject.org Date: Fri Jan 26 12:18:43 2018 -0500
Change the sandbox behavior on all failed opens() to EACCES
Previously, most disallowed open(O_RDONLY) attempts would EACCES, but others would fail with a crash. --- changes/bug16106 | 6 ++++++ src/common/sandbox.c | 8 ++------ 2 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/changes/bug16106 b/changes/bug16106 new file mode 100644 index 000000000..9142a37e3 --- /dev/null +++ b/changes/bug16106 @@ -0,0 +1,6 @@ + o Minor bugfixes (linux seccomp2 sandbox): + - Cause a wider variety of unpermitted open() calls to fail with the + EACCES error when the sandbox is running. This won't enable any + previously non-working functionality, but it should turn several cases + from crashes into sandbox warnings. Fixes bug 16106; bugfix on + 0.2.5.1-alpha. diff --git a/src/common/sandbox.c b/src/common/sandbox.c index 37f582048..043b8bf14 100644 --- a/src/common/sandbox.c +++ b/src/common/sandbox.c @@ -481,18 +481,14 @@ sb_open(scmp_filter_ctx ctx, sandbox_cfg_t *filter) } }
- rc = seccomp_rule_add_1(ctx, SCMP_ACT_ERRNO(EACCES), SCMP_SYS(open), - SCMP_CMP_MASKED(1, O_CLOEXEC|O_NONBLOCK|O_NOCTTY|O_NOFOLLOW, - O_RDONLY)); + rc = seccomp_rule_add_0(ctx, SCMP_ACT_ERRNO(EACCES), SCMP_SYS(open)); if (rc != 0) { log_err(LD_BUG,"(Sandbox) failed to add open syscall, received libseccomp " "error %d", rc); return rc; }
- rc = seccomp_rule_add_1(ctx, SCMP_ACT_ERRNO(EACCES), SCMP_SYS(openat), - SCMP_CMP_MASKED(2, O_CLOEXEC|O_NONBLOCK|O_NOCTTY|O_NOFOLLOW, - O_RDONLY)); + rc = seccomp_rule_add_0(ctx, SCMP_ACT_ERRNO(EACCES), SCMP_SYS(openat)); if (rc != 0) { log_err(LD_BUG,"(Sandbox) failed to add openat syscall, received " "libseccomp error %d", rc);