1923017 - Crash in [@ mozilla::net::CacheFileHandle::IsClosed]

Status: RESOLVED FIXED

(Core :: Networking: Cache, defect, P3)

Description

[Gabriele Svelto [:gsvelto]]

Crash report: https://crash-stats.mozilla.org/report/index/cd402b90-12b4-4521-8f35-723880241005

Reason:

SIGSEGV / SEGV_MAPERR

Top 10 frames:

0  libxul.so  std::__atomic_base<unsigned int>::load(std::memory_order) const  /builds/worker/fetches/sysroot-x86_64-linux-gnu/usr/include/c++/8/bits/atomic_base.h:396
0  libxul.so  mozilla::detail::IntrinsicMemoryOps<unsigned int, (mozilla::MemoryOrdering)1>...  mfbt/Atomics.h:199
0  libxul.so  mozilla::Atomic<bool, (mozilla::MemoryOrdering)1, void>::operator bool() const  mfbt/Atomics.h:500
0  libxul.so  mozilla::net::CacheFileHandle::IsClosed() const  netwerk/cache2/CacheFileIOManager.h:63
0  libxul.so  mozilla::net::CacheFileIOManager::Read(mozilla::net::CacheFileHandle*, long, ...  netwerk/cache2/CacheFileIOManager.cpp:1959
1  libxul.so  mozilla::net::CacheFileChunk::Read(mozilla::net::CacheFileHandle*, unsigned i...  netwerk/cache2/CacheFileChunk.cpp:360
1  libxul.so  mozilla::net::CacheFile::GetChunkLocked(unsigned int, mozilla::net::CacheFile...  netwerk/cache2/CacheFile.cpp:1484
2  libxul.so  mozilla::net::CacheFile::PreloadChunks(unsigned int)  netwerk/cache2/CacheFile.cpp:1615
3  libxul.so  mozilla::net::CacheFile::GetChunkLocked(unsigned int, mozilla::net::CacheFile...  netwerk/cache2/CacheFile.cpp:1451
4  libxul.so  mozilla::net::CacheFileInputStream::EnsureCorrectChunk(bool)  netwerk/cache2/CacheFileInputStream.cpp:592

This look like a NULL pointer access. The NULL file handle seem to have originated from here.

Comment 1

[Randell Jesup [:jesup] (needinfo me)]

So somehow mHandle is null.

Basically nothing has changed since Jun that goes anywhere near mHandle. (and probably nothing for quite a while before). Could this be a signature change? Perhaps crashes like https://crash-stats.mozilla.org/report/index/d1a605b0-8a7e-41d0-82f8-2a3540240729 ?
Yeah, that's the same stack; they stopped showing up in August when this started.

Comment 2

[Valentin Gosu [:valentin] (he/him)]

Attachment: Bug 1923017 - Fix null ptr deref in CacheFileIOManager::Read r=#necko

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/35824d5bf052
https://hg.mozilla.org/integration/autoland/rev/ac099aece561
Fix null ptr deref in CacheFileIOManager::Read r=necko-reviewers,jesup

Comment 4

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/ac099aece561