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| author | Taehee Yoo <ap420073@gmail.com> | 2018-10-21 00:00:08 +0900 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-11-03 13:28:01 +0100 |
| commit | 54451f60c8fa061af9051a53be9786393947367c (patch) | |
| tree | f3cda53f6b4f0a5d7bd082db8b78828faabb244d /net | |
| parent | 17b8b74c0f8dbf9b9e3301f9ca5b65dd1c079951 (diff) | |
| download | linux-54451f60c8fa061af9051a53be9786393947367c.tar.gz linux-54451f60c8fa061af9051a53be9786393947367c.tar.bz2 linux-54451f60c8fa061af9051a53be9786393947367c.zip | |
netfilter: xt_IDLETIMER: add sysfs filename checking routine
When IDLETIMER rule is added, sysfs file is created under
/sys/class/xt_idletimer/timers/
But some label name shouldn't be used.
".", "..", "power", "uevent", "subsystem", etc...
So that sysfs filename checking routine is needed.
test commands:
%iptables -I INPUT -j IDLETIMER --timeout 1 --label "power"
splat looks like:
[95765.423132] sysfs: cannot create duplicate filename '/devices/virtual/xt_idletimer/timers/power'
[95765.433418] CPU: 0 PID: 8446 Comm: iptables Not tainted 4.19.0-rc6+ #20
[95765.449755] Call Trace:
[95765.449755] dump_stack+0xc9/0x16b
[95765.449755] ? show_regs_print_info+0x5/0x5
[95765.449755] sysfs_warn_dup+0x74/0x90
[95765.449755] sysfs_add_file_mode_ns+0x352/0x500
[95765.449755] sysfs_create_file_ns+0x179/0x270
[95765.449755] ? sysfs_add_file_mode_ns+0x500/0x500
[95765.449755] ? idletimer_tg_checkentry+0x3e5/0xb1b [xt_IDLETIMER]
[95765.449755] ? rcu_read_lock_sched_held+0x114/0x130
[95765.449755] ? __kmalloc_track_caller+0x211/0x2b0
[95765.449755] ? memcpy+0x34/0x50
[95765.449755] idletimer_tg_checkentry+0x4e2/0xb1b [xt_IDLETIMER]
[ ... ]
Fixes: 0902b469bd25 ("netfilter: xtables: idletimer target implementation")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/xt_IDLETIMER.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/net/netfilter/xt_IDLETIMER.c b/net/netfilter/xt_IDLETIMER.c index c6acfc2d9c84..eb4cbd244c3d 100644 --- a/net/netfilter/xt_IDLETIMER.c +++ b/net/netfilter/xt_IDLETIMER.c @@ -114,6 +114,22 @@ static void idletimer_tg_expired(struct timer_list *t) schedule_work(&timer->work); } +static int idletimer_check_sysfs_name(const char *name, unsigned int size) +{ + int ret; + + ret = xt_check_proc_name(name, size); + if (ret < 0) + return ret; + + if (!strcmp(name, "power") || + !strcmp(name, "subsystem") || + !strcmp(name, "uevent")) + return -EINVAL; + + return 0; +} + static int idletimer_tg_create(struct idletimer_tg_info *info) { int ret; @@ -124,6 +140,10 @@ static int idletimer_tg_create(struct idletimer_tg_info *info) goto out; } + ret = idletimer_check_sysfs_name(info->label, sizeof(info->label)); + if (ret < 0) + goto out_free_timer; + sysfs_attr_init(&info->timer->attr.attr); info->timer->attr.attr.name = kstrdup(info->label, GFP_KERNEL); if (!info->timer->attr.attr.name) { |