5.15-stable review patch. If anyone has any objections, please let me know.
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From: Murad Masimov m.masimov@mt-integration.ru
[ Upstream commit 5b29891f91dfb8758baf1e2217bef4b16b2b165b ]
User-provided mount parameter acdirmax of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 4c9f948142a5 ("cifs: Add new mount parameter "acdirmax" to allow caching directory metadata") Signed-off-by: Murad Masimov m.masimov@mt-integration.ru Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/fs_context.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c index d86cbed997fdd..9b1c0e0dfc63b 100644 --- a/fs/cifs/fs_context.c +++ b/fs/cifs/fs_context.c @@ -1062,11 +1062,11 @@ static int smb3_fs_context_parse_param(struct fs_context *fc, ctx->acregmax = HZ * result.uint_32; break; case Opt_acdirmax: - ctx->acdirmax = HZ * result.uint_32; - if (ctx->acdirmax > CIFS_MAX_ACTIMEO) { + if (result.uint_32 > CIFS_MAX_ACTIMEO / HZ) { cifs_errorf(fc, "acdirmax too large\n"); goto cifs_parse_mount_err; } + ctx->acdirmax = HZ * result.uint_32; break; case Opt_actimeo: if (HZ * result.uint_32 > CIFS_MAX_ACTIMEO) {