diff options
Diffstat (limited to 'mozilla-1436242.patch')
| -rw-r--r-- | mozilla-1436242.patch | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/mozilla-1436242.patch b/mozilla-1436242.patch new file mode 100644 index 0000000..570b7c5 --- /dev/null +++ b/mozilla-1436242.patch @@ -0,0 +1,56 @@ + +# HG changeset patch +# User Jed Davis <jld@mozilla.com> +# Date 1526943705 21600 +# Node ID 6bb3adfa15c6877f7874429462dad88f8c978c4f +# Parent 4c71c8454879c841871ecf3afb7dbdc96bad97fc +Bug 1436242 - Avoid undefined behavior in IPC fd-passing code. r=froydnj + +MozReview-Commit-ID: 3szIPUssgF5 + +diff --git a/ipc/chromium/src/chrome/common/ipc_channel_posix.cc b/ipc/chromium/src/chrome/common/ipc_channel_posix.cc +--- a/ipc/chromium/src/chrome/common/ipc_channel_posix.cc ++++ b/ipc/chromium/src/chrome/common/ipc_channel_posix.cc +@@ -418,20 +418,37 @@ bool Channel::ChannelImpl::ProcessIncomi + const int* fds; + unsigned num_fds; + unsigned fds_i = 0; // the index of the first unused descriptor + + if (input_overflow_fds_.empty()) { + fds = wire_fds; + num_fds = num_wire_fds; + } else { +- const size_t prev_size = input_overflow_fds_.size(); +- input_overflow_fds_.resize(prev_size + num_wire_fds); +- memcpy(&input_overflow_fds_[prev_size], wire_fds, +- num_wire_fds * sizeof(int)); ++ // This code may look like a no-op in the case where ++ // num_wire_fds == 0, but in fact: ++ // ++ // 1. wire_fds will be nullptr, so passing it to memcpy is ++ // undefined behavior according to the C standard, even though ++ // the memcpy length is 0. ++ // ++ // 2. prev_size will be an out-of-bounds index for ++ // input_overflow_fds_; this is undefined behavior according to ++ // the C++ standard, even though the element only has its ++ // pointer taken and isn't accessed (and the corresponding ++ // operation on a C array would be defined). ++ // ++ // UBSan makes #1 a fatal error, and assertions in libstdc++ do ++ // the same for #2 if enabled. ++ if (num_wire_fds > 0) { ++ const size_t prev_size = input_overflow_fds_.size(); ++ input_overflow_fds_.resize(prev_size + num_wire_fds); ++ memcpy(&input_overflow_fds_[prev_size], wire_fds, ++ num_wire_fds * sizeof(int)); ++ } + fds = &input_overflow_fds_[0]; + num_fds = input_overflow_fds_.size(); + } + + // The data for the message we're currently reading consists of any data + // stored in incoming_message_ followed by data in input_buf_ (followed by + // other messages). + + |