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pgsql: Fix race condition in pg_ctl reading postmaster.pid.

From: Heikki Linnakangas <heikki(dot)linnakangas(at)iki(dot)fi>
To: pgsql-committers(at)postgresql(dot)org
Subject: pgsql: Fix race condition in pg_ctl reading postmaster.pid.
Date: 2012-10-15 07:59:54
Message-ID: E1TNfac-0008Nv-P8@gemulon.postgresql.org (view raw or flat)
Thread:
Lists: pgsql-committers
Fix race condition in pg_ctl reading postmaster.pid.

If postmaster changed postmaster.pid while pg_ctl was reading it, pg_ctl
could overrun the buffer it allocated for the file. Fix by reading the
whole file to memory with one read() call.

initdb contains an identical copy of the readfile() function, but the files
that initdb reads are static, not modified concurrently. Nevertheless, add
a simple bounds-check there, if only to silence static analysis tools.

Per report from Dave Vitek. Backpatch to all supported branches.

Branch
------
REL9_2_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/540374768d75b8f0b477274dc98c7c52602b2923

Modified Files
--------------
src/bin/initdb/initdb.c |    9 +++--
src/bin/pg_ctl/pg_ctl.c |   88 +++++++++++++++++++++++++++++++----------------
2 files changed, 63 insertions(+), 34 deletions(-)

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Next:From: Heikki LinnakangasDate: 2012-10-15 08:04:07
Subject: pgsql: Remove comment that is no longer true.
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Subject: pgsql: Split up process latch initialization for more-fail-softbehavio

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