Avoid passing unintended format codes to snprintf(). timeofday() assumed that the output of pg_strftime() could not contain % signs, other than the one it explicitly asks for with %%. However, we don't have that guarantee with respect to the time zone name (%Z). A crafted time zone setting could abuse the subsequent snprintf() call, resulting in crashes or disclosure of server memory.
To fix, split the pg_strftime() call into two and then treat the outputs as literal strings, not a snprintf format string. The extra pg_strftime() call doesn't really cost anything, since the bulk of the conversion work was done by pg_localtime(). Also, adjust buffer widths so that we're not risking string truncation during the snprintf() step, as that would create a hazard of producing mis-encoded output. This also fixes a latent portability issue: the format string expects an int, but tp.tv_usec is long int on many platforms. Reported-by: Xint Code Author: Tom Lane <[email protected]> Reviewed-by: John Naylor <[email protected]> Backpatch-through: 14 Security: CVE-2026-6474 Branch ------ REL_18_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/ba27389c2cfa1485bbe26754b23d3f6b4c4e72e2 Author: Tom Lane <[email protected]> Modified Files -------------- src/backend/utils/adt/timestamp.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
