[PATCH 03/12] ima: Free the entire rule when deleting a list of rules

[Mimi Zohar]

On Thu, 2020-06-25 at 17:07 -0400, Mimi Zohar wrote:
> On Mon, 2020-06-22 at 19:32 -0500, Tyler Hicks wrote:
> > Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry
> > members, such as .fsname and .keyrings, when deleting a list of rules.
> > 
> > This fixes a memory leak seen when loading by a valid rule that contains
> > an additional piece of allocated memory, such as an fsname, followed by
> > an invalid rule that triggers a policy load failure:
> > 
> >  # echo -e "dont_measure fsname=securityfs\nbad syntax" > \
> >     /sys/kernel/security/ima/policy
> >  -bash: echo: write error: Invalid argument
> >  # echo scan > /sys/kernel/debug/kmemleak
> >  # cat /sys/kernel/debug/kmemleak
> >  unreferenced object 0xffff9bab67ca12c0 (size 16):
> >    comm "tee", pid 684, jiffies 4295212803 (age 252.344s)
> >    hex dump (first 16 bytes):
> >      73 65 63 75 72 69 74 79 66 73 00 6b 6b 6b 6b a5  securityfs.kkkk.
> >    backtrace:
> >      [<00000000adc80b1b>] kstrdup+0x2e/0x60
> >      [<00000000d504cb0d>] ima_parse_add_rule+0x7d4/0x1020
> >      [<00000000444825ac>] ima_write_policy+0xab/0x1d0
> >      [<000000002b7f0d6c>] vfs_write+0xde/0x1d0
> >      [<0000000096feedcf>] ksys_write+0x68/0xe0
> >      [<0000000052b544a2>] do_syscall_64+0x56/0xa0
> >      [<000000007ead1ba7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > 
> > Fixes: f1b08bbcbdaf ("ima: define a new policy condition based on the filesystem name")
> > Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy")
> > Signed-off-by: Tyler Hicks <tyhicks at linux.microsoft.com>
> 
> Your decision, but you might consider squashing this patch with 3/12.
>  Everything all together in one patch.

Oops, that was the comment for 4/12.

Mimi