Message ID | 20190514074300.42588-1-yuehaibing@huawei.com |
---|---|
State | Changes Requested |
Delegated to: | David Miller |
Headers | show |
Series | ppp: deflate: Fix possible crash in deflate_init | expand |
On Tue, May 14, 2019 at 03:43:00PM +0800, YueHaibing wrote: > > If ppp_deflate fails to register in deflate_init, > module initialization failed out, however > ppp_deflate_draft may has been regiestred and not > unregistered before return. > Then the seconed modprobe will trigger crash like this. > > Reported-by: Hulk Robot <hulkci@huawei.com> > Signed-off-by: YueHaibing <yuehaibing@huawei.com> > --- > drivers/net/ppp/ppp_deflate.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/drivers/net/ppp/ppp_deflate.c b/drivers/net/ppp/ppp_deflate.c > index b5edc7f..2829efe 100644 > --- a/drivers/net/ppp/ppp_deflate.c > +++ b/drivers/net/ppp/ppp_deflate.c > @@ -610,12 +610,16 @@ static void z_incomp(void *arg, unsigned char *ibuf, int icnt) > > static int __init deflate_init(void) > { > - int answer = ppp_register_compressor(&ppp_deflate); > - if (answer == 0) > - printk(KERN_INFO > - "PPP Deflate Compression module registered\n"); > + int answer; > + > + answer = ppp_register_compressor(&ppp_deflate); > + if (answer) > + return answer; > + > + pr_info("PPP Deflate Compression module registered\n"); > ppp_register_compressor(&ppp_deflate_draft); > - return answer; > + > + return 0; > } > I'd be cleaner to also check for ppp_deflate_draft registration failure IMHO (and print the log line only if both compressors get registered successfully).
On 2019/5/14 22:05, Guillaume Nault wrote: > On Tue, May 14, 2019 at 03:43:00PM +0800, YueHaibing wrote: >> >> If ppp_deflate fails to register in deflate_init, >> module initialization failed out, however >> ppp_deflate_draft may has been regiestred and not >> unregistered before return. >> Then the seconed modprobe will trigger crash like this. >> >> Reported-by: Hulk Robot <hulkci@huawei.com> >> Signed-off-by: YueHaibing <yuehaibing@huawei.com> >> --- >> drivers/net/ppp/ppp_deflate.c | 14 +++++++++----- >> 1 file changed, 9 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/net/ppp/ppp_deflate.c b/drivers/net/ppp/ppp_deflate.c >> index b5edc7f..2829efe 100644 >> --- a/drivers/net/ppp/ppp_deflate.c >> +++ b/drivers/net/ppp/ppp_deflate.c >> @@ -610,12 +610,16 @@ static void z_incomp(void *arg, unsigned char *ibuf, int icnt) >> >> static int __init deflate_init(void) >> { >> - int answer = ppp_register_compressor(&ppp_deflate); >> - if (answer == 0) >> - printk(KERN_INFO >> - "PPP Deflate Compression module registered\n"); >> + int answer; >> + >> + answer = ppp_register_compressor(&ppp_deflate); >> + if (answer) >> + return answer; >> + >> + pr_info("PPP Deflate Compression module registered\n"); >> ppp_register_compressor(&ppp_deflate_draft); >> - return answer; >> + >> + return 0; >> } >> > I'd be cleaner to also check for ppp_deflate_draft registration failure > IMHO (and print the log line only if both compressors get registered > successfully). Ok, will send v2 to do that, thanks! > > . >
diff --git a/drivers/net/ppp/ppp_deflate.c b/drivers/net/ppp/ppp_deflate.c index b5edc7f..2829efe 100644 --- a/drivers/net/ppp/ppp_deflate.c +++ b/drivers/net/ppp/ppp_deflate.c @@ -610,12 +610,16 @@ static void z_incomp(void *arg, unsigned char *ibuf, int icnt) static int __init deflate_init(void) { - int answer = ppp_register_compressor(&ppp_deflate); - if (answer == 0) - printk(KERN_INFO - "PPP Deflate Compression module registered\n"); + int answer; + + answer = ppp_register_compressor(&ppp_deflate); + if (answer) + return answer; + + pr_info("PPP Deflate Compression module registered\n"); ppp_register_compressor(&ppp_deflate_draft); - return answer; + + return 0; } static void __exit deflate_cleanup(void)
BUG: unable to handle kernel paging request at ffffffffa018f000 PGD 3270067 P4D 3270067 PUD 3271063 PMD 2307eb067 PTE 0 Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 4138 Comm: modprobe Not tainted 5.1.0-rc7+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 RIP: 0010:ppp_register_compressor+0x3e/0xd0 [ppp_generic] Code: 98 4a 3f e2 48 8b 15 c1 67 00 00 41 8b 0c 24 48 81 fa 40 f0 19 a0 75 0e eb 35 48 8b 12 48 81 fa 40 f0 19 a0 74 RSP: 0018:ffffc90000d93c68 EFLAGS: 00010287 RAX: ffffffffa018f000 RBX: ffffffffa01a3000 RCX: 000000000000001a RDX: ffff888230c750a0 RSI: 0000000000000000 RDI: ffffffffa019f000 RBP: ffffc90000d93c80 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa0194080 R13: ffff88822ee1a700 R14: 0000000000000000 R15: ffffc90000d93e78 FS: 00007f2339557540(0000) GS:ffff888237a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffa018f000 CR3: 000000022bde4000 CR4: 00000000000006f0 Call Trace: ? 0xffffffffa01a3000 deflate_init+0x11/0x1000 [ppp_deflate] ? 0xffffffffa01a3000 do_one_initcall+0x6c/0x3cc ? kmem_cache_alloc_trace+0x248/0x3b0 do_init_module+0x5b/0x1f1 load_module+0x1db1/0x2690 ? m_show+0x1d0/0x1d0 __do_sys_finit_module+0xc5/0xd0 __x64_sys_finit_module+0x15/0x20 do_syscall_64+0x6b/0x1d0 entry_SYSCALL_64_after_hwframe+0x49/0xbe If ppp_deflate fails to register in deflate_init, module initialization failed out, however ppp_deflate_draft may has been regiestred and not unregistered before return. Then the seconed modprobe will trigger crash like this. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> --- drivers/net/ppp/ppp_deflate.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)