96322 - Should null protect nsCRT::HashCode()

Status: RESOLVED FIXED

Description

[Paul Chen]

The reason we crash in bug 91726 is because we pass a null for the char*
parameter to nsCRT::HashCode(). There are some people who believe that
nsCRT::HashCode() should at least not die when given such input.

Comment 1

[Paul Chen]

taking this bug

Comment 2

[Paul Chen]

marking p3, minor, and future

Comment 3

[Aleksey Nogin]

Just saw another crash in nsCRT::HashCode - see bug 118492

Comment 4

[Doug Turner (:dougt)]

*** Bug 118492 has been marked as a duplicate of this bug. ***

Comment 5

[Doug Turner (:dougt)]

From dup:

Just saw Mozilla crash in nsCRT::HashCode()

GDB output:
[...]
Program terminated with signal 11, Segmentation fault.
[...]
(gdb) bt
#0  0x40117cb8 in nsCRT::HashCode () from /usr/lib/libxpcom.so
#1  0x4011ab31 in nsCStringKey::HashCode () from /usr/lib/libxpcom.so
#2  0x4011a08f in PL_HashTableFinalize () from /usr/lib/libxpcom.so
#3  0x401c28c6 in PL_HashTableLookup () from /usr/lib/libplds4.so
#4  0x4011a455 in nsHashtable::Get () from /usr/lib/libxpcom.so
#5  0x4011b48b in nsSupportsHashtable::Get () from /usr/lib/libxpcom.so
#6  0x41072f94 in NSGetModule () from /usr/lib/mozilla/components/libjar50.so
#7  0x408365a2 in NSGetModule () from /usr/lib/mozilla/components/libnecko.so
#8  0x40836600 in NSGetModule () from /usr/lib/mozilla/components/libnecko.so
#9  0x407e1256 in NSGetModule () from /usr/lib/mozilla/components/libnecko.so
#10 0x407e1160 in NSGetModule () from /usr/lib/mozilla/components/libnecko.so
#11 0x4015c86b in nsThreadPoolRunnable::Run () from /usr/lib/libxpcom.so
#12 0x4015b32b in nsThread::Main () from /usr/lib/libxpcom.so
#13 0x401ea4e4 in _pt_root () from /usr/lib/libnspr4.so
#14 0x401fac6f in pthread_start_thread (arg=0x434ffbe0) at manager.c:284

Comment 6

[Doug Turner (:dougt)]

scc's change removed the check for null in the hashing algorithm.  

http://bonsai.mozilla.org/cvsview2.cgi?diff_mode=context&whitespace_mode=show&root=/cvsroot&subdir=mozilla/xpcom/ds&command=DIFF_FRAMESET&file=nsCRT.cpp&rev2=3.38&rev1=3.37

I do not see the harm in placing it back.

Comment 7

[Doug Turner (:dougt)]

Created attachment 64695 [details] [diff] [review]
protects against null input.

Comment 8

[Doug Turner (:dougt)]

Created attachment 64696 [details] [diff] [review]
protects against null input.

Comment 9

[Doug Turner (:dougt)]

brendan, alecf, can you review this?

Comment 10

[Alec Flett]

Comment on attachment 64696 [details] [diff] [review]
protects against null input.

sure
sr=alecf

Comment 11

[Suresh Duddi (gone)]

r=dp

Comment 12

[Doug Turner (:dougt)]

Thanks reviewers.


Checking in nsCRT.cpp;
/cvsroot/mozilla/xpcom/ds/nsCRT.cpp,v  <--  nsCRT.cpp
new revision: 3.49; previous revision: 3.48
done