diff mbox series

[net,2/6] net: mscc: ocelot: avoid use after free with deleted tc-trap rules

Message ID 20220503115728.834457-3-vladimir.oltean@nxp.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Ocelot VCAP fixes | expand

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Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Vladimir Oltean May 3, 2022, 11:57 a.m. UTC
The error path of ocelot_flower_parse() removes a VCAP filter from
ocelot->traps, but the main deletion path - ocelot_vcap_filter_del() -
does not.

So functions such as felix_update_trapping_destinations() can still
access the freed VCAP filter via ocelot->traps.

Fix this bug by removing the filter from ocelot->traps when it gets
deleted.

Fixes: e42bd4ed09aa ("net: mscc: ocelot: keep traps in a list")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/net/ethernet/mscc/ocelot_vcap.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Vladimir Oltean May 4, 2022, 9:10 p.m. UTC | #1
On Tue, May 03, 2022 at 02:57:24PM +0300, Vladimir Oltean wrote:
> The error path of ocelot_flower_parse() removes a VCAP filter from
> ocelot->traps, but the main deletion path - ocelot_vcap_filter_del() -
> does not.
> 
> So functions such as felix_update_trapping_destinations() can still
> access the freed VCAP filter via ocelot->traps.
> 
> Fix this bug by removing the filter from ocelot->traps when it gets
> deleted.
> 
> Fixes: e42bd4ed09aa ("net: mscc: ocelot: keep traps in a list")
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
>  drivers/net/ethernet/mscc/ocelot_vcap.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/ethernet/mscc/ocelot_vcap.c b/drivers/net/ethernet/mscc/ocelot_vcap.c
> index 1e74bdb215ec..571d43e59f63 100644
> --- a/drivers/net/ethernet/mscc/ocelot_vcap.c
> +++ b/drivers/net/ethernet/mscc/ocelot_vcap.c
> @@ -1232,6 +1232,8 @@ static void ocelot_vcap_block_remove_filter(struct ocelot *ocelot,
>  		if (ocelot_vcap_filter_equal(filter, tmp)) {
>  			ocelot_vcap_filter_del_aux_resources(ocelot, tmp);
>  			list_del(&tmp->list);
> +			if (!list_empty(&tmp->trap_list))
> +				list_del(&tmp->trap_list);
>  			kfree(tmp);
>  		}
>  	}
> -- 
> 2.25.1
>

This change introduces other breakage, please drop this patch set and
allow me to come up with a different solution.
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mscc/ocelot_vcap.c b/drivers/net/ethernet/mscc/ocelot_vcap.c
index 1e74bdb215ec..571d43e59f63 100644
--- a/drivers/net/ethernet/mscc/ocelot_vcap.c
+++ b/drivers/net/ethernet/mscc/ocelot_vcap.c
@@ -1232,6 +1232,8 @@  static void ocelot_vcap_block_remove_filter(struct ocelot *ocelot,
 		if (ocelot_vcap_filter_equal(filter, tmp)) {
 			ocelot_vcap_filter_del_aux_resources(ocelot, tmp);
 			list_del(&tmp->list);
+			if (!list_empty(&tmp->trap_list))
+				list_del(&tmp->trap_list);
 			kfree(tmp);
 		}
 	}