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| author | Takashi Iwai <tiwai@suse.de> | 2014-11-10 11:50:21 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-21 09:23:07 -0800 |
| commit | 511f1df2f2d1871f3a90852aa33dfb6c8d47ba08 (patch) | |
| tree | 8534f34c76d2616c30fd41fb73fe919229c0b898 /drivers/net | |
| parent | b42813b304a937efec5c7566df400b0f4272ecb0 (diff) | |
| download | lwn-511f1df2f2d1871f3a90852aa33dfb6c8d47ba08.tar.gz lwn-511f1df2f2d1871f3a90852aa33dfb6c8d47ba08.zip | |
net: ppp: Don't call bpf_prog_create() in ppp_lock
[ Upstream commit 5748eb8f8e989a9da1ac7c96dc73d68cbdedf7df ]
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 <stefan.seyfried@googlemail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ppp/ppp_generic.c | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index 90c639b0f18d..17ecdd60cf6c 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; } |