Prevent some buffer overruns in spell.c's parsing of affix files.

parse_affentry() and addCompoundAffixFlagValue() each collect fields
from an affix file into working buffers of size BUFSIZ.  They failed
to defend against overlength fields, so that a malicious affix file
could cause a stack smash.  BUFSIZ (typically 8K) is certainly way
longer than any reasonable affix field, but let's fix this while
we're closing holes in this area.

I chose to do this by silently truncating the input before it can
overrun the buffer, using logic comparable to the existing logic in
get_nextfield().  Certainly there's at least as good an argument for
raising an error, but for now let's follow the existing precedent.

Reported-by: Igor Stepansky <[email protected]>
Author: Tom Lane <[email protected]>
Reviewed-by: Andrey Borodin <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch-through: 14

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/d7970e7e951bb39b0d5d7ae633fc7f1af54aa932

Modified Files
--------------
src/backend/tsearch/spell.c | 34 ++++++++++++++++++++++++----------
1 file changed, 24 insertions(+), 10 deletions(-)

Reply via email to