| Message ID | 20210713130344.473646-1-mudongliangabcd@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v2] audit: fix memory leak in nf_tables_commit | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Guessed tree name to be net-next |
| netdev/subject_prefix | warning | Target tree name not specified in the subject |
| netdev/cc_maintainers | success | CCed 10 of 10 maintainers |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 16 this patch: 16 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 30 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 16 this patch: 16 |
| netdev/header_inline | success | Link |
Dongliang Mu <mudongliangabcd@gmail.com> wrote: > In nf_tables_commit, if nf_tables_commit_audit_alloc fails, it does not > free the adp variable. > > Fix this by freeing the linked list with head adl. > > backtrace: > kmalloc include/linux/slab.h:591 [inline] > kzalloc include/linux/slab.h:721 [inline] > nf_tables_commit_audit_alloc net/netfilter/nf_tables_api.c:8439 [inline] > nf_tables_commit+0x16e/0x1760 net/netfilter/nf_tables_api.c:8508 > nfnetlink_rcv_batch+0x512/0xa80 net/netfilter/nfnetlink.c:562 > nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] > nfnetlink_rcv+0x1fa/0x220 net/netfilter/nfnetlink.c:652 > netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] > netlink_unicast+0x2c7/0x3e0 net/netlink/af_netlink.c:1340 > netlink_sendmsg+0x36b/0x6b0 net/netlink/af_netlink.c:1929 > sock_sendmsg_nosec net/socket.c:702 [inline] > sock_sendmsg+0x56/0x80 net/socket.c:722 > > Reported-by: syzbot <syzkaller@googlegroups.com> > Reported-by: kernel test robot <lkp@intel.com> > Fixes: c520292f29b8 ("audit: log nftables configuration change events once per table") > Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> > --- > v1->v2: fix the compile issue > net/netfilter/nf_tables_api.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c > index 390d4466567f..7f45b291be13 100644 > --- a/net/netfilter/nf_tables_api.c > +++ b/net/netfilter/nf_tables_api.c > @@ -8444,6 +8444,16 @@ static int nf_tables_commit_audit_alloc(struct list_head *adl, > return 0; > } > > +static void nf_tables_commit_free(struct list_head *adl) nf_tables_commit_audit_free? Aside from that, there should be a followup patch (for nf-next), adding empty inline functions in case of CONFIG_AUDITSYSCALL=n. Right now it does pointless aggregation for the AUDIT=n case.
On Tue, Jul 13, 2021 at 9:21 PM Florian Westphal <fw@strlen.de> wrote: > > Dongliang Mu <mudongliangabcd@gmail.com> wrote: > > In nf_tables_commit, if nf_tables_commit_audit_alloc fails, it does not > > free the adp variable. > > > > Fix this by freeing the linked list with head adl. > > > > backtrace: > > kmalloc include/linux/slab.h:591 [inline] > > kzalloc include/linux/slab.h:721 [inline] > > nf_tables_commit_audit_alloc net/netfilter/nf_tables_api.c:8439 [inline] > > nf_tables_commit+0x16e/0x1760 net/netfilter/nf_tables_api.c:8508 > > nfnetlink_rcv_batch+0x512/0xa80 net/netfilter/nfnetlink.c:562 > > nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] > > nfnetlink_rcv+0x1fa/0x220 net/netfilter/nfnetlink.c:652 > > netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] > > netlink_unicast+0x2c7/0x3e0 net/netlink/af_netlink.c:1340 > > netlink_sendmsg+0x36b/0x6b0 net/netlink/af_netlink.c:1929 > > sock_sendmsg_nosec net/socket.c:702 [inline] > > sock_sendmsg+0x56/0x80 net/socket.c:722 > > > > Reported-by: syzbot <syzkaller@googlegroups.com> > > Reported-by: kernel test robot <lkp@intel.com> > > Fixes: c520292f29b8 ("audit: log nftables configuration change events once per table") > > Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> > > --- > > v1->v2: fix the compile issue > > net/netfilter/nf_tables_api.c | 12 ++++++++++++ > > 1 file changed, 12 insertions(+) > > > > diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c > > index 390d4466567f..7f45b291be13 100644 > > --- a/net/netfilter/nf_tables_api.c > > +++ b/net/netfilter/nf_tables_api.c > > @@ -8444,6 +8444,16 @@ static int nf_tables_commit_audit_alloc(struct list_head *adl, > > return 0; > > } > > > > +static void nf_tables_commit_free(struct list_head *adl) > > nf_tables_commit_audit_free? What do you mean? Modify the name of newly added function to nf_tables_commit_audit_free? > > Aside from that, there should be a followup patch (for nf-next), > adding empty inline functions in case of CONFIG_AUDITSYSCALL=n. I see. I prefer to send them (two implementations of the newly added function) in version v2. > > Right now it does pointless aggregation for the AUDIT=n case.
Dongliang Mu <mudongliangabcd@gmail.com> wrote: > > > +static void nf_tables_commit_free(struct list_head *adl) > > > > nf_tables_commit_audit_free? > > What do you mean? Modify the name of newly added function to > nf_tables_commit_audit_free? Yes, this function is audit related, and it does the inverse of existing '...audit_alloc'.
On Tue, Jul 13, 2021 at 11:31 PM Florian Westphal <fw@strlen.de> wrote: > > Dongliang Mu <mudongliangabcd@gmail.com> wrote: > > > > +static void nf_tables_commit_free(struct list_head *adl) > > > > > > nf_tables_commit_audit_free? > > > > What do you mean? Modify the name of newly added function to > > nf_tables_commit_audit_free? > > Yes, this function is audit related, and it does the inverse > of existing '...audit_alloc'. Hi Florian, I double-check the patch, and it seems there is no need to send a followup patch (nf-next). I will send a v3 patch with the new function name. Best regards Dongliang Mu
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 390d4466567f..7f45b291be13 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8444,6 +8444,16 @@ static int nf_tables_commit_audit_alloc(struct list_head *adl, return 0; } +static void nf_tables_commit_free(struct list_head *adl) +{ + struct nft_audit_data *adp, *adn; + + list_for_each_entry_safe(adp, adn, adl, list) { + list_del(&adp->list); + kfree(adp); + } +} + static void nf_tables_commit_audit_collect(struct list_head *adl, struct nft_table *table, u32 op) { @@ -8508,6 +8518,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) ret = nf_tables_commit_audit_alloc(&adl, trans->ctx.table); if (ret) { nf_tables_commit_chain_prepare_cancel(net); + nf_tables_commit_free(&adl); return ret; } if (trans->msg_type == NFT_MSG_NEWRULE || @@ -8517,6 +8528,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) ret = nf_tables_commit_chain_prepare(net, chain); if (ret < 0) { nf_tables_commit_chain_prepare_cancel(net); + nf_tables_commit_free(&adl); return ret; } }
In nf_tables_commit, if nf_tables_commit_audit_alloc fails, it does not free the adp variable. Fix this by freeing the linked list with head adl. backtrace: kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] nf_tables_commit_audit_alloc net/netfilter/nf_tables_api.c:8439 [inline] nf_tables_commit+0x16e/0x1760 net/netfilter/nf_tables_api.c:8508 nfnetlink_rcv_batch+0x512/0xa80 net/netfilter/nfnetlink.c:562 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] nfnetlink_rcv+0x1fa/0x220 net/netfilter/nfnetlink.c:652 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x2c7/0x3e0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x36b/0x6b0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:702 [inline] sock_sendmsg+0x56/0x80 net/socket.c:722 Reported-by: syzbot <syzkaller@googlegroups.com> Reported-by: kernel test robot <lkp@intel.com> Fixes: c520292f29b8 ("audit: log nftables configuration change events once per table") Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> --- v1->v2: fix the compile issue net/netfilter/nf_tables_api.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)