libio: Attempt wide backup free only for non-legacy code

_wide_data and _mode are not available in legacy code, so do not attempt
to free the wide backup buffer in legacy code.

Resolves: BZ #32137 and BZ #27821

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit ae4d44b1d5)
This commit is contained in:
Siddhesh Poyarekar 2024-09-03 14:58:33 -04:00 committed by Florian Weimer
parent 09fb06d3d6
commit 37214df5f1
2 changed files with 3 additions and 1 deletions

2
NEWS
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@ -26,6 +26,7 @@ The following bugs are resolved with this release:
[24816] Fix tst-nss-files-hosts-long on single-stack hosts
[25812] Libio vtable protection is sometimes only partially enforced
[27576] gmon: improve mcount overflow handling
[27821] ungetc: Fix backup buffer leak on program exit
[28838] FAIL: elf/tst-p_align3
[28846] CMSG_NXTHDR may trigger -Wstrict-overflow warning
[28850] linux: __get_nprocs_sched reads uninitialized memory from the stack
@ -100,6 +101,7 @@ The following bugs are resolved with this release:
[31965] rseq extension mechanism does not work as intended
[31968] mremap implementation in C does not handle arguments correctly
[32052] Name space violation in fortify wrappers
[32137] libio: Attempt wide backup free only for non-legacy code
Security related changes:

View File

@ -799,7 +799,7 @@ _IO_unbuffer_all (void)
/* Free up the backup area if it was ever allocated. */
if (_IO_have_backup (fp))
_IO_free_backup_area (fp);
if (fp->_mode > 0 && _IO_have_wbackup (fp))
if (!legacy && fp->_mode > 0 && _IO_have_wbackup (fp))
_IO_free_wbackup_area (fp);
if (! (fp->_flags & _IO_UNBUFFERED)