Messages in this thread | | | Subject | Re: [PATCH] ipmi_si: fix use-after-free of resource->name | From | Yang Yingliang <> | Date | Sat, 26 Jan 2019 09:41:37 +0800 |
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On 2019/1/26 4:35, Corey Minyard wrote: > On Fri, Jan 25, 2019 at 10:30:59AM +0800, Yang Yingliang wrote: >> When we excute the following commands, we got oops >> rmmod ipmi_si >> cat /proc/ioports >> > snip... > >> If io_setup is called successful in try_smi_init() but try_smi_init() >> goes out_err before calling ipmi_register_smi(), so ipmi_unregister_smi() >> will not be called while removing module. It leads to the resource that >> allocated in io_setup() can not be freed, but the name(DEVICE_NAME) of >> resource is freed while removing the module. It causes use-after-free >> when cat /proc/ioports. >> >> Fix this by calling shutdown_smi() while removing the module and don't >> call release_region() if request_region() is not called to avoid error >> prints. >> >> Fixes: 93c303d2045b ("ipmi_si: Clean up shutdown a bit") >> Cc: stable@vger.kernel.org >> Reported-by: NuoHan Qiao <qiaonuohan@huawei.com> >> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> >> --- >> drivers/char/ipmi/ipmi_si_intf.c | 2 ++ >> drivers/char/ipmi/ipmi_si_port_io.c | 3 +++ >> 2 files changed, 5 insertions(+) >> >> diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c >> index dc8603d..635e98a 100644 >> --- a/drivers/char/ipmi/ipmi_si_intf.c >> +++ b/drivers/char/ipmi/ipmi_si_intf.c >> @@ -2235,6 +2235,8 @@ static void cleanup_one_si(struct smi_info *smi_info) >> >> if (smi_info->intf) >> ipmi_unregister_smi(smi_info->intf); >> + else >> + shutdown_smi(smi_info); > This is completely the wrong way to fix this. The general principle is > that a function cleans up for itself if it returns an error. If you > add hacks other places for a function failing you end up with a mess. > > I think the right way to fix this is to add something like: > > if (rv && new_smi->io.io_size && smi_info->io.io_cleanup) { > smi_info->io.io_cleanup(&smi_info->io); > smi_info->io.io_cleanup = NULL; > } > > at the end of try_smi_init(). > > -corey OK, I will do some test, and send v2 later.
Thanks, Yang >> >> if (smi_info->pdev) { >> if (smi_info->pdev_registered) >> diff --git a/drivers/char/ipmi/ipmi_si_port_io.c b/drivers/char/ipmi/ipmi_si_port_io.c >> index ef6dffc..0c46a3f 100644 >> --- a/drivers/char/ipmi/ipmi_si_port_io.c >> +++ b/drivers/char/ipmi/ipmi_si_port_io.c >> @@ -53,6 +53,9 @@ static void port_cleanup(struct si_sm_io *io) >> unsigned int addr = io->addr_data; >> int idx; >> >> + if (io->regsize != 1 && io->regsize != 2 && io->regsize != 4) >> + return; >> + >> if (addr) { >> for (idx = 0; idx < io->io_size; idx++) >> release_region(addr + idx * io->regspacing, >> -- >> 1.8.3 >> >> > . >
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