Skip to content

Commit

Permalink
net: genetlink: always allocate separate attrs for dumpit ops
Browse files Browse the repository at this point in the history
Individual dumpit ops (start, dumpit, done) are locked by genl_lock
if !family->parallel_ops. However, multiple
genl_family_rcv_msg_dumpit() calls may in in flight in parallel.
Each has a separate struct genl_dumpit_info allocated
but they share the same family->attrbuf. Fix this by allocating separate
memory for attrs for dumpit ops, for non-parallel_ops (for parallel_ops
it is done already).

Reported-by: syzbot+495688b736534bb6c6ad@syzkaller.appspotmail.com
Reported-by: syzbot+ff59dc711f2cff879a05@syzkaller.appspotmail.com
Reported-by: syzbot+dbe02e13bcce52bcf182@syzkaller.appspotmail.com
Reported-by: syzbot+9cb7edb2906ea1e83006@syzkaller.appspotmail.com
Fixes: bf813b0 ("net: genetlink: parse attrs and store in contect info struct during dumpit")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
  • Loading branch information
Jiri Pirko authored and Jakub Kicinski committed Oct 9, 2019
1 parent 48423dd commit ab5b526
Showing 1 changed file with 17 additions and 11 deletions.
28 changes: 17 additions & 11 deletions net/netlink/genetlink.c
Original file line number Diff line number Diff line change
@@ -474,15 +474,16 @@ genl_family_rcv_msg_attrs_parse(const struct genl_family *family,
struct netlink_ext_ack *extack,
const struct genl_ops *ops,
int hdrlen,
enum genl_validate_flags no_strict_flag)
enum genl_validate_flags no_strict_flag,
bool parallel)
{
enum netlink_validation validate = ops->validate & no_strict_flag ?
NL_VALIDATE_LIBERAL :
NL_VALIDATE_STRICT;
struct nlattr **attrbuf;
int err;

if (family->maxattr && family->parallel_ops) {
if (parallel) {
attrbuf = kmalloc_array(family->maxattr + 1,
sizeof(struct nlattr *), GFP_KERNEL);
if (!attrbuf)
@@ -493,17 +494,18 @@ genl_family_rcv_msg_attrs_parse(const struct genl_family *family,

err = __nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
family->policy, validate, extack);
if (err && family->maxattr && family->parallel_ops) {
if (err && parallel) {
kfree(attrbuf);
return ERR_PTR(err);
}
return attrbuf;
}

static void genl_family_rcv_msg_attrs_free(const struct genl_family *family,
struct nlattr **attrbuf)
struct nlattr **attrbuf,
bool parallel)
{
if (family->maxattr && family->parallel_ops)
if (parallel)
kfree(attrbuf);
}

@@ -542,7 +544,7 @@ static int genl_lock_done(struct netlink_callback *cb)
rc = ops->done(cb);
genl_unlock();
}
genl_family_rcv_msg_attrs_free(info->family, info->attrs);
genl_family_rcv_msg_attrs_free(info->family, info->attrs, true);
genl_dumpit_info_free(info);
return rc;
}
@@ -555,7 +557,7 @@ static int genl_parallel_done(struct netlink_callback *cb)

if (ops->done)
rc = ops->done(cb);
genl_family_rcv_msg_attrs_free(info->family, info->attrs);
genl_family_rcv_msg_attrs_free(info->family, info->attrs, true);
genl_dumpit_info_free(info);
return rc;
}
@@ -585,15 +587,16 @@ static int genl_family_rcv_msg_dumpit(const struct genl_family *family,

attrs = genl_family_rcv_msg_attrs_parse(family, nlh, extack,
ops, hdrlen,
GENL_DONT_VALIDATE_DUMP_STRICT);
GENL_DONT_VALIDATE_DUMP_STRICT,
true);
if (IS_ERR(attrs))
return PTR_ERR(attrs);

no_attrs:
/* Allocate dumpit info. It is going to be freed by done() callback. */
info = genl_dumpit_info_alloc();
if (!info) {
genl_family_rcv_msg_attrs_free(family, attrs);
genl_family_rcv_msg_attrs_free(family, attrs, true);
return -ENOMEM;
}

@@ -645,7 +648,9 @@ static int genl_family_rcv_msg_doit(const struct genl_family *family,

attrbuf = genl_family_rcv_msg_attrs_parse(family, nlh, extack,
ops, hdrlen,
GENL_DONT_VALIDATE_STRICT);
GENL_DONT_VALIDATE_STRICT,
family->maxattr &&
family->parallel_ops);
if (IS_ERR(attrbuf))
return PTR_ERR(attrbuf);

@@ -671,7 +676,8 @@ static int genl_family_rcv_msg_doit(const struct genl_family *family,
family->post_doit(ops, skb, &info);

out:
genl_family_rcv_msg_attrs_free(family, attrbuf);
genl_family_rcv_msg_attrs_free(family, attrbuf,
family->maxattr && family->parallel_ops);

return err;
}

0 comments on commit ab5b526

Please sign in to comment.