Обсуждение: pgsql: Fix potential stack overflow in incremental backup.
Fix potential stack overflow in incremental backup. The user can set RELSEG_SIZE to a high number at compile time, so we can't use it to control the size of an array on the stack: it could be many gigabytes in size. On closer inspection, we don't really need that intermediate array anyway. Let's just write directly into the output array, and then perform the absolute->relative adjustment in place. This fixes new code from commit dc212340058. Reviewed-by: Robert Haas <robertmhaas@gmail.com> Discussion: https://postgr.es/m/CA%2BhUKG%2B2hZ0sBztPW4mkLfng0qfkNtAHFUfxOMLizJ0BPmi5%2Bg%40mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/d8f5acbdb9b22106db583e3cbb177d34e6b18eeb Modified Files -------------- src/backend/backup/basebackup_incremental.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-)
Hi Thomas, On Thu, Apr 11, 2024 at 01:53:24AM +0000, Thomas Munro wrote: > Fix potential stack overflow in incremental backup. > > The user can set RELSEG_SIZE to a high number at compile time, so we > can't use it to control the size of an array on the stack: it could be > many gigabytes in size. On closer inspection, we don't really need that > intermediate array anyway. Let's just write directly into the output > array, and then perform the absolute->relative adjustment in place. > This fixes new code from commit dc212340058. + * file just as if this were not an incremental backup. The contents of the + * relative_block_numbers array is unspecified in this case. Perhaps you mean s/is/are/ here? The contents are what's not specified. -- Michael
Вложения
On Thu, Apr 11, 2024 at 2:28 PM Michael Paquier <michael@paquier.xyz> wrote: > + * file just as if this were not an incremental backup. The contents of the > + * relative_block_numbers array is unspecified in this case. > > Perhaps you mean s/is/are/ here? The contents are what's not > specified. Thanks, fixed. Duh.