Messages in this thread | | | Date | Fri, 16 Nov 2012 13:17:04 +0200 | From | Kalle Valo <> | Subject | Re: [PATCH 4/5] ath6kl/wmi.c: eliminate possible double free |
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Hi Julia,
On 10/21/2012 01:52 PM, Julia Lawall wrote: > From: Julia Lawall <Julia.Lawall@lip6.fr> > > This makes two changes. In ath6kl_wmi_cmd_send, a call to dev_kfree_skb on > the skb argument is added to the initial sanity check to more completely > establish the invariant that ath6kl_wmi_cmd_send owns its skb argument. > Then, in ath6kl_wmi_sync_point, on failure of the call to > ath6kl_wmi_cmd_send, the clearing of the local skb variable is moved up, so > that the error-handling code at the end of the function does not free it > again. > > A simplified version of the semantic match that finds this problem is as > follows: (http://coccinelle.lip6.fr/) > > // <smpl> > @r@ > identifier f,free,a; > parameter list[n] ps; > type T; > expression e; > @@ > > f(ps,T a,...) { > ... when any > when != a = e > if(...) { ... free(a); ... return ...; } > ... when any > } > > @@ > identifier r.f,r.free; > expression x,a; > expression list[r.n] xs; > @@ > > * x = f(xs,a,...); > if (...) { ... free(a); ... return ...; } > // </smpl> > > Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
I think this patch which is commited to ath6kl.git has fixed this.
commit 0616dc1f2bef563d7916c0dcedbb1bff7d9bd80b Author: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com> Date: Tue Aug 14 10:10:33 2012 +0530
ath6kl: Fix potential skb double free in ath6kl_wmi_sync_point()
skb given to ath6kl_control_tx() is owned by ath6kl_control_tx(). Calling function should not free the skb for error cases. This is found during code review.
kvalo: fix a checkpatch warning in ath6kl_wmi_cmd_send()
Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com> Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
https://github.com/kvalo/ath6kl/commit/0616dc1f2bef563d7916c0dcedbb1bff7d9bd80b
If you have the time, I would appreciate if you could take a look and confirm.
Kalle
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