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Re: [PATCH v5] libio: do not attempt to free wide buffers of legacy streams [BZ #24228]
* Dmitry V. Levin:
> Commit a601b74d31ca086de38441d316a3dee24c866305 aka glibc-2.23~693
> ("In preparation for fixing BZ#16734, fix failure in misc/tst-error1-mem
> when _G_HAVE_MMAP is turned off.") introduced a regression:
> _IO_unbuffer_all now invokes _IO_wsetb to free wide buffers of all
> files, including legacy standard files which are small statically
> allocated objects that do not have wide buffers and the _mode member,
> causing memory corruption.
>
> Another memory corruption in _IO_unbuffer_all happens when -1
> is assigned to the _mode member of legacy standard files that
> do not have it.
>
> [BZ #24228]
> * libio/genops.c (_IO_unbuffer_all)
> [SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)]: Do not attempt to free wide
> buffers and access _IO_FILE_complete members of legacy libio streams.
> * libio/tst-bz24228.c: New file.
> * libio/tst-bz24228.map: Likewise.
> * libio/Makefile [build-shared] (tests): Add tst-bz24228.
> [build-shared] (generated): Add tst-bz24228.mtrace and
> tst-bz24228.check.
> [run-built-tests && build-shared] (tests-special): Add
> $(objpfx)tst-bz24228-mem.out.
> (LDFLAGS-tst-bz24228, tst-bz24228-ENV): New variables.
> ($(objpfx)tst-bz24228-mem.out): New rule.
This version looks fine to me. Thanks.
Sorry, it took me a while to really understand this issue.
Florian