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 7489161b1852390b4413d57f2457cd40b34da6cc ]
User-provided mount parameter acregmax 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: 5780464614f6 ("cifs: Add new parameter "acregmax" for distinct file and directory metadata timeout") 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 fb3651513f83a..d86cbed997fdd 100644 --- a/fs/cifs/fs_context.c +++ b/fs/cifs/fs_context.c @@ -1055,11 +1055,11 @@ static int smb3_fs_context_parse_param(struct fs_context *fc, ctx->got_wsize = true; break; case Opt_acregmax: - ctx->acregmax = HZ * result.uint_32; - if (ctx->acregmax > CIFS_MAX_ACTIMEO) { + if (result.uint_32 > CIFS_MAX_ACTIMEO / HZ) { cifs_errorf(fc, "acregmax too large\n"); goto cifs_parse_mount_err; } + ctx->acregmax = HZ * result.uint_32; break; case Opt_acdirmax: ctx->acdirmax = HZ * result.uint_32;