The patch titled Subject: mm: swap: correctly use maxpages in swapon syscall to avoid potential deadloop has been added to the -mm mm-new branch. Its filename is mm-swap-correctly-use-maxpages-in-swapon-syscall-to-avoid-potensial-deadloop-fix.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------ From: Kemeng Shi shikemeng@huaweicloud.com Subject: mm: swap: correctly use maxpages in swapon syscall to avoid potential deadloop Date: Fri, 18 Jul 2025 14:51:39 +0800
ensure si->pages == si->max - 1 after setup_swap_extents()
Link: https://lkml.kernel.org/r/20250522122554.12209-3-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20250718065139.61989-1-shikemeng@huaweicloud.com Fixes: 661383c6111a ("mm: swap: relaim the cached parts that got scanned") Signed-off-by: Kemeng Shi shikemeng@huaweicloud.com Reviewed-by: Baoquan He bhe@redhat.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Kairui Song kasong@tencent.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/swapfile.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/mm/swapfile.c~mm-swap-correctly-use-maxpages-in-swapon-syscall-to-avoid-potensial-deadloop-fix +++ a/mm/swapfile.c @@ -3357,6 +3357,12 @@ SYSCALL_DEFINE2(swapon, const char __use error = nr_extents; goto bad_swap_unlock_inode; } + if (si->pages != si->max - 1) { + pr_err("swap:%u != (max:%u - 1)\n", si->pages, si->max); + error = -EINVAL; + goto bad_swap_unlock_inode; + } + maxpages = si->max;
/* OK, set up the swap map and apply the bad block list */ _
Patches currently in -mm which might be from shikemeng@huaweicloud.com are
mm-swap-move-nr_swap_pages-counter-decrement-from-folio_alloc_swap-to-swap_range_alloc.patch mm-swap-correctly-use-maxpages-in-swapon-syscall-to-avoid-potensial-deadloop.patch mm-swap-correctly-use-maxpages-in-swapon-syscall-to-avoid-potensial-deadloop-fix.patch mm-swap-fix-potensial-buffer-overflow-in-setup_clusters.patch mm-swap-remove-stale-comment-stale-comment-in-cluster_alloc_swap_entry.patch