Messages in this thread | | | Date | Tue, 27 Feb 2024 14:48:59 +0200 | Subject | Re: [PATCH net v2] rtnetlink: fix error logic of IFLA_BRIDGE_FLAGS writing back | From | Nikolay Aleksandrov <> |
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On 2/27/24 14:11, Lin Ma wrote: > In the commit d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks > IFLA_BRIDGE_MODE length"), an adjustment was made to the old loop logic > in the function `rtnl_bridge_setlink` to enable the loop to also check > the length of the IFLA_BRIDGE_MODE attribute. However, this adjustment > removed the `break` statement and led to an error logic of the flags > writing back at the end of this function. > > if (have_flags) > memcpy(nla_data(attr), &flags, sizeof(flags)); > // attr should point to IFLA_BRIDGE_FLAGS NLA !!! > > Before the mentioned commit, the `attr` is granted to be IFLA_BRIDGE_FLAGS. > However, this is not necessarily true fow now as the updated loop will let > the attr point to the last NLA, even an invalid NLA which could cause > overflow writes. > > This patch introduces a new variable `br_flag` to save the NLA pointer > that points to IFLA_BRIDGE_FLAGS and uses it to resolve the mentioned > error logic. > > Fixes: d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length") > Signed-off-by: Lin Ma <linma@zju.edu.cn> > --- > v1 -> v2: rename the br_flag to br_flags_attr which offers better > description suggested by Nikolay. > > net/core/rtnetlink.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) >
As Jiri pointed out, you should wait a day before posting another version. The patch itself looks good to me:
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
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