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author | Volker Lendecke <vl@samba.org> | 2009-02-14 18:01:20 +0100 |
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committer | Günther Deschner <gd@samba.org> | 2009-02-17 10:20:55 +0100 |
commit | ea192f08e609fa4c4a48df1b27874b9ae2c1fa40 (patch) | |
tree | f15277612eaf3157cc37ff0fa0dc635966b2195b /WHATSNEW4.txt | |
parent | 612c5e746bd4d0059eb8bcb8dbb4944db155f071 (diff) | |
download | samba-ea192f08e609fa4c4a48df1b27874b9ae2c1fa40.tar.gz samba-ea192f08e609fa4c4a48df1b27874b9ae2c1fa40.tar.bz2 samba-ea192f08e609fa4c4a48df1b27874b9ae2c1fa40.zip |
Fix an invalid typecasting
entry->num_of_strings is a uint16_t. Casting it with
(int *)&entry->num_of_strings
is wrong, because it gives add_string_to_array the illusion that the object
"num" points to is an int, which it is not.
In case we are running on a machine where "int" is 32 or 64 bits long, what
happens with that cast? "add_string_to_array" interprets the byte field that
starts where "num_of_strings" starts as an int. Under very particular
circumstances this might work in a limited number of cases: When the byte order
of an int is such that the lower order bits of the int are stored first, the
subsequent bytes which do not belong to the uint16_t anymore happen to be 0 and
the result of the increment still fits into the first 2 bytes of that int, i.e.
the result is < 65536.
The correct solution to this problem is to use the implicit type conversion
that happens when an assignment is done.
BTW, this bug is found if you compile with -O3 -Wall, it shows up as a warning:
rpc_server/srv_eventlog_lib.c:574: warning: dereferencing type-punned pointer
will break strict-aliasing rules
Thanks,
Volker
Diffstat (limited to 'WHATSNEW4.txt')
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