On Fri, Oct 05, 2018 at 06:24:42PM +0200, Richard Weinberger wrote:
Sasha,
Am Freitag, 5. Oktober 2018, 18:17:50 CEST schrieb Sasha Levin:
From: Richard Weinberger <[email protected]>
[ Upstream commit 37f31b6ca4311b94d985fb398a72e5399ad57925 ]
The requested device name can be NULL or an empty string.
Check for that and refuse to continue. UBIFS has to do this manually
since we cannot use mount_bdev(), which checks for this condition.
Fixes: 1e51764a3c2ac ("UBIFS: add new flash file system")
Reported-by: [email protected]
Signed-off-by: Richard Weinberger <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
I'm not sure whether it makes sense to apply this patch to stable.
1. You need to be the real root to hit this code path.
2. Access is read-only, for an attacker it is useless.
If we look at the code:
if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
return ERR_PTR(-EINVAL);
/* ubi:NAME method */
if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
name can be NULL, so we access just a few bytes.
Thanks,
//richard
Hi Richard,
I wasn't really looking at it from a security perspective. My thought
process was that if a user (root or not) is doing action A, expecting
result B but instead unexpectedly sees result C then it's a bug worth
fixing in stable.
If you think it's a risky change for stable I'd be happy to drop it.
--
Thanks,
Sasha
