From 642929a2ded029aac13b8cb91bc9b7c088ddb57f Mon Sep 17 00:00:00 2001 From: Rafael Aquini Date: Fri, 5 Nov 2021 13:37:22 -0700 Subject: [PATCH] mm/swapfile: fix an integer overflow in swap_show() This one is just a minor nuisance for people going through /proc/swaps if any of their swapareas is bigger than, or equal to 1073741824 pages (4TB). seq_printf() format string casts as uint the conversion from pages to KB, and that will overflow in the aforementioned case. Albeit being almost unthinkable that someone would actually set up such big of a single swaparea, there is a ticket recently filed against RHEL: https://bugzilla.redhat.com/show_bug.cgi?id=2008812 Given that all other codesites that use format strings for the same swap pages-to-KB conversion do cast it as ulong, this patch just follows suit. Link: https://lkml.kernel.org/r/20211006184011.2579054-1-aquini@redhat.com Signed-off-by: Rafael Aquini Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 42027d2..353e5bd 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2763,7 +2763,7 @@ static int swap_show(struct seq_file *swap, void *v) struct swap_info_struct *si = v; struct file *file; int len; - unsigned int bytes, inuse; + unsigned long bytes, inuse; if (si == SEQ_START_TOKEN) { seq_puts(swap, "Filename\t\t\t\tType\t\tSize\t\tUsed\t\tPriority\n"); @@ -2775,7 +2775,7 @@ static int swap_show(struct seq_file *swap, void *v) file = si->swap_file; len = seq_file_path(swap, file, " \t\n\\"); - seq_printf(swap, "%*s%s\t%u\t%s%u\t%s%d\n", + seq_printf(swap, "%*s%s\t%lu\t%s%lu\t%s%d\n", len < 40 ? 40 - len : 1, " ", S_ISBLK(file_inode(file)->i_mode) ? "partition" : "file\t", -- 2.7.4