Messages in this thread | | | Date | Mon, 7 Nov 2011 10:19:39 -0500 | From | Ted Ts'o <> | Subject | Re: [PATCH v2] ext4: fix NULL pointer dereference from orig_data in fill_super and remount. |
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On Mon, Nov 07, 2011 at 11:01:51PM +0900, Namjae Jeon wrote: > Fix NULL pointer dereference from orig_data in fill_super and remount. > > Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Um, did you even try to test this patch before submitting it?
#1: kstrdup() return NULL if data is NULL
#2: The kernel's printk and sprintf functions will translate sprintf(buf, "%s", NULL) by filling in the string "NULL"
#3: The only use of orig_data is a cosmetic one, of printing out the mount options which are passed in.
#4: If the user doesn't specify any mount options, data is NULL, and your patch would cause those mounts to fail with ENOMEM.
In summary, there is no problem here; a pendant might complain that it's possible for data to be non-NULL, and for orig_data to be null of the kstrdup failed, but in that case, other memory allocations done later in ext4_fill_super() will almost have certainly failed, so in practice won't get as far as the printk.
- Ted
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