Messages in this thread | | | Subject | Re: [PATCH -next] netlabel: Fix memory leak in netlbl_mgmt_add_common | From | Liu Shixin <> | Date | Thu, 10 Jun 2021 18:45:15 +0800 |
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On 2021/6/10 11:08, Dongliang Mu wrote: > On Thu, Jun 10, 2021 at 9:31 AM Liu Shixin <liushixin2@huawei.com> wrote: >> Hulk Robot reported memory leak in netlbl_mgmt_add_common. >> The problem is non-freed map in case of netlbl_domhsh_add() failed. >> >> BUG: memory leak >> unreferenced object 0xffff888100ab7080 (size 96): >> comm "syz-executor537", pid 360, jiffies 4294862456 (age 22.678s) >> hex dump (first 32 bytes): >> 05 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ >> fe 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 ................ >> backtrace: >> [<0000000008b40026>] netlbl_mgmt_add_common.isra.0+0xb2a/0x1b40 >> [<000000003be10950>] netlbl_mgmt_add+0x271/0x3c0 >> [<00000000c70487ed>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 >> [<000000001f2ff614>] genl_rcv_msg+0x2bf/0x4f0 >> [<0000000089045792>] netlink_rcv_skb+0x134/0x3d0 >> [<0000000020e96fdd>] genl_rcv+0x24/0x40 >> [<0000000042810c66>] netlink_unicast+0x4a0/0x6a0 >> [<000000002e1659f0>] netlink_sendmsg+0x789/0xc70 >> [<000000006e43415f>] sock_sendmsg+0x139/0x170 >> [<00000000680a73d7>] ____sys_sendmsg+0x658/0x7d0 >> [<0000000065cbb8af>] ___sys_sendmsg+0xf8/0x170 >> [<0000000019932b6c>] __sys_sendmsg+0xd3/0x190 >> [<00000000643ac172>] do_syscall_64+0x37/0x90 >> [<000000009b79d6dc>] entry_SYSCALL_64_after_hwframe+0x44/0xae >> >> Fixes: 63c416887437 ("netlabel: Add network address selectors to the NetLabel/LSM domain mapping") >> Reported-by: Hulk Robot <hulkci@huawei.com> >> Signed-off-by: Liu Shixin <liushixin2@huawei.com> >> --- >> net/netlabel/netlabel_mgmt.c | 20 ++++++++++++++++---- >> 1 file changed, 16 insertions(+), 4 deletions(-) >> >> diff --git a/net/netlabel/netlabel_mgmt.c b/net/netlabel/netlabel_mgmt.c >> index e664ab990941..e7f00c0f441e 100644 >> --- a/net/netlabel/netlabel_mgmt.c >> +++ b/net/netlabel/netlabel_mgmt.c >> @@ -191,6 +191,12 @@ static int netlbl_mgmt_add_common(struct genl_info *info, >> entry->family = AF_INET; >> entry->def.type = NETLBL_NLTYPE_ADDRSELECT; >> entry->def.addrsel = addrmap; >> + >> + ret_val = netlbl_domhsh_add(entry, audit_info); >> + if (ret_val != 0) { >> + kfree(map); >> + goto add_free_addrmap; >> + } >> #if IS_ENABLED(CONFIG_IPV6) >> } else if (info->attrs[NLBL_MGMT_A_IPV6ADDR]) { >> struct in6_addr *addr; >> @@ -243,13 +249,19 @@ static int netlbl_mgmt_add_common(struct genl_info *info, >> entry->family = AF_INET6; >> entry->def.type = NETLBL_NLTYPE_ADDRSELECT; >> entry->def.addrsel = addrmap; >> + >> + ret_val = netlbl_domhsh_add(entry, audit_info); >> + if (ret_val != 0) { >> + kfree(map); >> + goto add_free_addrmap; >> + } >> #endif /* IPv6 */ >> + } else { >> + ret_val = netlbl_domhsh_add(entry, audit_info); >> + if (ret_val != 0) >> + goto add_free_addrmap; >> } >> >> - ret_val = netlbl_domhsh_add(entry, audit_info); >> - if (ret_val != 0) >> - goto add_free_addrmap; >> - > Hi Shixin, > > I have a small suggestion about this patch: you can move the variable > map out of if/else if branches, like the following code snippet. > > Be aware to assign the variable map to NULL at first. Then kfree in > the last else branch will do nothing. > > I don't test the following diff, if there are any issues, please let me know. > > diff --git a/net/netlabel/netlabel_mgmt.c b/net/netlabel/netlabel_mgmt.c > index ca52f5085989..1824bcd2272b 100644 > --- a/net/netlabel/netlabel_mgmt.c > +++ b/net/netlabel/netlabel_mgmt.c > @@ -78,6 +78,7 @@ static int netlbl_mgmt_add_common(struct genl_info *info, > { > int ret_val = -EINVAL; > struct netlbl_domaddr_map *addrmap = NULL; > + struct netlbl_domaddr4_map *map = NULL; > struct cipso_v4_doi *cipsov4 = NULL; > #if IS_ENABLED(CONFIG_IPV6) > struct calipso_doi *calipso = NULL; > @@ -147,7 +148,6 @@ static int netlbl_mgmt_add_common(struct genl_info *info, > if (info->attrs[NLBL_MGMT_A_IPV4ADDR]) { > struct in_addr *addr; > struct in_addr *mask; > - struct netlbl_domaddr4_map *map; > > addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL); > if (addrmap == NULL) { > @@ -195,7 +195,6 @@ static int netlbl_mgmt_add_common(struct genl_info *info, > } else if (info->attrs[NLBL_MGMT_A_IPV6ADDR]) { > struct in6_addr *addr; > struct in6_addr *mask; > - struct netlbl_domaddr6_map *map; > > addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL); > if (addrmap == NULL) { > @@ -247,8 +246,10 @@ static int netlbl_mgmt_add_common(struct genl_info *info, > } > > ret_val = netlbl_domhsh_add(entry, audit_info); > - if (ret_val != 0) > + if (ret_val != 0) { > + kfree(map); > goto add_free_addrmap; > + } > > return 0; > The type of map can be struct netlbl_domaddr4_map or struct netlbl_domaddr6_map under different conditions. It seems like I can't put them together simply.
Thanks, > > > >> return 0; >> >> add_free_addrmap: >> -- >> 2.18.0.huawei.25 >> > . >
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