lib: free pagelist on error in iov_iter_extract_pages()#811
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lib: free pagelist on error in iov_iter_extract_pages()#811blktests-ci[bot] wants to merge 1 commit intolinus-master_basefrom
blktests-ci[bot] wants to merge 1 commit intolinus-master_basefrom
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Since 'iov_iter_extract_pages()' may allocate new pagelist if the passed
one isn't large enough, the worst-case scenario may be:
...
struct page *stack_pages[SMALL];
struct page **pages = stack_pages;
...
if (iov_iter_extract_pages(i..., &pages, ...) <= 0) {
/* Even in case of error, new pagelist may be allocated */
if (pages != stack_pages)
kvfree(pages); [1]
/* The rest of error handling and return */
}
/* Regular flow */
...
if (pages != stack_pages)
kvfree(pages);
...
return 0;
If you're unlucky so SMALL amount of pages wasn't enough and new
pagelist was allocated, missing [1] causes the memory leak similar
to one I've recently observed and fixed for 6.12 in [2]. So adjust
'iov_iter_extract_pages()' to make such a cleanup itself rather than
rely on caller's handling on error paths, thus making [1] not needed.
[2] https://lore.kernel.org/stable/20260505094529.406783-1-dmantipov@yandex.ru/T/#u
Suggested-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Author
|
Upstream branch: 6d35786 |
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Pull request for series with
subject: lib: free pagelist on error in iov_iter_extract_pages()
version: 1
url: https://patchwork.kernel.org/project/linux-block/list/?series=1091577