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io_uring: Fix release of pinned pages when __io_uaddr_map fails

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Looking at the error path of __io_uaddr_map, if we fail after pinning
the pages for any reasons, ret will be set to -EINVAL and the error
handler won't properly release the pinned pages.

I didn't manage to trigger it without forcing a failure, but it can
happen in real life when memory is heavily fragmented.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Fixes: 223ef47431 ("io_uring: don't allow IORING_SETUP_NO_MMAP rings on highmem pages")
Link: https://lore.kernel.org/r/20240313213912.1920-1-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Gabriel Krisman Bertazi 2024-03-13 17:39:12 -04:00 committed by Jens Axboe
parent 9219e4a9d4
commit 67d1189d10
1 changed files with 13 additions and 9 deletions
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22
io_uring/io_uring.c
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@ -2714,7 +2714,7 @@ static void *__io_uaddr_map(struct page ***pages, unsigned short *npages,
struct page **page_array; struct page **page_array;
unsigned int nr_pages; unsigned int nr_pages;
void *page_addr; void *page_addr;
int ret, i; int ret, i, pinned;
*npages = 0; *npages = 0;
@ -2728,12 +2728,12 @@ static void *__io_uaddr_map(struct page ***pages, unsigned short *npages,
if (!page_array) if (!page_array)
return ERR_PTR(-ENOMEM); return ERR_PTR(-ENOMEM);
ret = pin_user_pages_fast(uaddr, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
page_array); pinned = pin_user_pages_fast(uaddr, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
if (ret != nr_pages) { page_array);
err: if (pinned != nr_pages) {
io_pages_free(&page_array, ret > 0 ? ret : 0); ret = (pinned < 0) ? pinned : -EFAULT;
return ret < 0 ? ERR_PTR(ret) : ERR_PTR(-EFAULT); goto free_pages;
} }
page_addr = page_address(page_array[0]); page_addr = page_address(page_array[0]);
@ -2747,7 +2747,7 @@ err:
* didn't support this feature. * didn't support this feature.
*/ */
if (PageHighMem(page_array[i])) if (PageHighMem(page_array[i]))
goto err; goto free_pages;
/* /*
* No support for discontig pages for now, should either be a * No support for discontig pages for now, should either be a
@ -2756,13 +2756,17 @@ err:
* just fail them with EINVAL. * just fail them with EINVAL.
*/ */
if (page_address(page_array[i]) != page_addr) if (page_address(page_array[i]) != page_addr)
goto err; goto free_pages;
page_addr += PAGE_SIZE; page_addr += PAGE_SIZE;
} }
*pages = page_array; *pages = page_array;
*npages = nr_pages; *npages = nr_pages;
return page_to_virt(page_array[0]); return page_to_virt(page_array[0]);
free_pages:
io_pages_free(&page_array, pinned > 0 ? pinned : 0);
return ERR_PTR(ret);
} }
static void *io_rings_map(struct io_ring_ctx *ctx, unsigned long uaddr, static void *io_rings_map(struct io_ring_ctx *ctx, unsigned long uaddr,