Bug 197390

Summary:

Add assertion to check whether shm files have maximum FileProtection of CompleteUnlessOpen

Product:

WebKit

Reporter:

Sihui Liu <sihui_liu>

Component:

New Bugs

Assignee:

Sihui Liu <sihui_liu>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

achristensen, benjamin, cdumez, cgarcia, cmarcelo, commit-queue, dbates, ews-watchlist, ggaren, koivisto, webkit-bug-importer

Priority:

Keywords:

InRadar

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

See Also:

https://bugs.webkit.org/show_bug.cgi?id=222054

Attachments:

Description	Flags
Patch	none

Description Sihui Liu 2019-04-29 15:11:27 PDT

We have seen crashes where process gets killed because it tries accessing shm file after device is locked. We are suspecting this is because database protection class of shm file is set to be Complete by apps after it's created with lower protection level.

Comment 1 Sihui Liu 2019-04-29 15:15:08 PDT

<rdar://problem/42685773>

Comment 2 Sihui Liu 2019-04-29 15:29:23 PDT

Created attachment 368502 [details]
Patch

Comment 3 Alex Christensen 2019-04-29 16:16:51 PDT

Comment on attachment 368502 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=368502&action=review

> Source/WebCore/platform/sql/SQLiteDatabase.cpp:154
> +        RELEASE_ASSERT(FileSystem::isSafeToUseMemoryMapForPath(shmFileName));

Why not just call makeSafeToUseMemoryMapForPath?

Comment 4 Sihui Liu 2019-04-29 17:48:55 PDT

(In reply to Alex Christensen from comment #3)
> Comment on attachment 368502 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=368502&action=review
> 
> > Source/WebCore/platform/sql/SQLiteDatabase.cpp:154
> > +        RELEASE_ASSERT(FileSystem::isSafeToUseMemoryMapForPath(shmFileName));
> 
> Why not just call makeSafeToUseMemoryMapForPath?

If the crash is caused by the shm file being unsafe for mmap, we probably need change in sqlite instead of WebKit to ensure shm file is in correct protection class when the file is being used.

Comment 5 Geoffrey Garen 2019-05-02 13:23:43 PDT

Comment on attachment 368502 [details]
Patch

r=me

Comment 6 WebKit Commit Bot 2019-05-03 14:24:11 PDT

Comment on attachment 368502 [details]
Patch

Clearing flags on attachment: 368502

Committed r244921: <https://trac.webkit.org/changeset/244921>

Comment 7 WebKit Commit Bot 2019-05-03 14:24:13 PDT

All reviewed patches have been landed.  Closing bug.