From 5748eb8f8e989a9da1ac7c96dc73d68cbdedf7df Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 10 Nov 2014 11:50:21 +0100 Subject: [PATCH] net: ppp: Don't call bpf_prog_create() in ppp_lock In ppp_ioctl(), bpf_prog_create() is called inside ppp_lock, which eventually calls vmalloc() and hits BUG_ON() in vmalloc.c. This patch works around the problem by moving the allocation outside the lock. The bug was revealed by the recent change in net/core/filter.c, as it allocates via vmalloc() instead of kmalloc() now. Reported-and-tested-by: Stefan Seyfried Signed-off-by: Takashi Iwai Signed-off-by: David S. Miller --- drivers/net/ppp/ppp_generic.c | 40 +++++++++++++++++------------------ 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index 68c3a3f4e0ab..794a47329368 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -755,23 +755,23 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) err = get_filter(argp, &code); if (err >= 0) { + struct bpf_prog *pass_filter = NULL; struct sock_fprog_kern fprog = { .len = err, .filter = code, }; - ppp_lock(ppp); - if (ppp->pass_filter) { - bpf_prog_destroy(ppp->pass_filter); - ppp->pass_filter = NULL; + err = 0; + if (fprog.filter) + err = bpf_prog_create(&pass_filter, &fprog); + if (!err) { + ppp_lock(ppp); + if (ppp->pass_filter) + bpf_prog_destroy(ppp->pass_filter); + ppp->pass_filter = pass_filter; + ppp_unlock(ppp); } - if (fprog.filter != NULL) - err = bpf_prog_create(&ppp->pass_filter, - &fprog); - else - err = 0; kfree(code); - ppp_unlock(ppp); } break; } @@ -781,23 +781,23 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) err = get_filter(argp, &code); if (err >= 0) { + struct bpf_prog *active_filter = NULL; struct sock_fprog_kern fprog = { .len = err, .filter = code, }; - ppp_lock(ppp); - if (ppp->active_filter) { - bpf_prog_destroy(ppp->active_filter); - ppp->active_filter = NULL; + err = 0; + if (fprog.filter) + err = bpf_prog_create(&active_filter, &fprog); + if (!err) { + ppp_lock(ppp); + if (ppp->active_filter) + bpf_prog_destroy(ppp->active_filter); + ppp->active_filter = active_filter; + ppp_unlock(ppp); } - if (fprog.filter != NULL) - err = bpf_prog_create(&ppp->active_filter, - &fprog); - else - err = 0; kfree(code); - ppp_unlock(ppp); } break; } -- 2.20.1