linux-kernel - [PATCH] tmpfs: fix mounts when size is less than the page size

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <11941279021705-git-send-email-mike@marineau.org>
Date:	Sat,  3 Nov 2007 15:11:42 -0700
From:	Michael Marineau <mike@...ineau.org>
To:	linux-kernel@...r.kernel.org
Cc:	trivial@...nel.org, Michael Marineau <mike@...ineau.org>
Subject: [PATCH] tmpfs: fix mounts when size is less than the page size

When tmpfs is mounted with a size less than one page the number of blocks
is set to 0 which makes the tmpfs mount unlimited. This can lead to a quick
and surprising death is someone typos a tmpfs mount command and writes to much.

tmpfs can still be mounted as unlimited if size or nr_blocks is exactly 0.

Signed-off-by: Michael Marineau <mike@...ineau.org>
---
 mm/shmem.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 253d205..66b07f2 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2138,6 +2138,8 @@ static int shmem_parse_options(char *options, int *mode, uid_t *uid,
 			if (*rest)
 				goto bad_val;
 			*blocks = size >> PAGE_CACHE_SHIFT;
+			if (size && blocks == 0)
+				blocks = 1;
 		} else if (!strcmp(this_char,"nr_blocks")) {
 			*blocks = memparse(value,&rest);
 			if (*rest)
-- 
1.5.1.6

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/