From: Christophe Leroy <christophe.leroy@csgroup.eu> To: Yi Zhuang <zhuangyi1@huawei.com> Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, hegdevasant@linux.vnet.ibm.com, paulus@samba.org, benh@kernel.crashing.org Subject: Re: [PATCH v2] powerpc/rtas_flash: fix a potential buffer overflow Date: Wed, 14 Jul 2021 18:52:24 +0200 [thread overview] Message-ID: <20210714185224.Horde.SuBZAzTXvfB6J6HsqQkOog6@messagerie.c-s.fr> (raw) In-Reply-To: <20210714122753.76021-1-zhuangyi1@huawei.com> Yi Zhuang <zhuangyi1@huawei.com> a écrit : > Since snprintf() returns the possible output size instead of the > actual output size, the available flash_msg length returned by > get_validate_flash_msg may exceed the given buffer limit when > simple_read_from_buffer calls copy_to_user > > Reported-by: kernel test robot <lkp@intel.com> > Fixes: a94a14720eaf5 powerpc/rtas_flash: Fix validate_flash buffer > overflow issue > Signed-off-by: Yi Zhuang <zhuangyi1@huawei.com> > --- > arch/powerpc/kernel/rtas_flash.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kernel/rtas_flash.c > b/arch/powerpc/kernel/rtas_flash.c > index a99179d83538..062f0724c2ff 100644 > --- a/arch/powerpc/kernel/rtas_flash.c > +++ b/arch/powerpc/kernel/rtas_flash.c > @@ -470,9 +470,14 @@ static int get_validate_flash_msg(struct > rtas_validate_flash_t *args_buf, > if (args_buf->status >= VALIDATE_TMP_UPDATE) { > n = sprintf(msg, "%d\n", args_buf->update_results); > if ((args_buf->update_results >= VALIDATE_CUR_UNKNOWN) || > - (args_buf->update_results == VALIDATE_TMP_UPDATE)) > + (args_buf->update_results == VALIDATE_TMP_UPDATE)) { > n += snprintf(msg + n, msglen - n, "%s\n", > args_buf->buf); > + if (n >= msglen) { n cannot be greater than msglen > + n = msglen; > + printk(KERN_ERR "FLASH: msg too long.\n"); > + } > + } > } else { > n = sprintf(msg, "%d\n", args_buf->status); > } > -- > 2.26.0.106.g9fadedd
WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@csgroup.eu> To: Yi Zhuang <zhuangyi1@huawei.com> Cc: hegdevasant@linux.vnet.ibm.com, paulus@samba.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] powerpc/rtas_flash: fix a potential buffer overflow Date: Wed, 14 Jul 2021 18:52:24 +0200 [thread overview] Message-ID: <20210714185224.Horde.SuBZAzTXvfB6J6HsqQkOog6@messagerie.c-s.fr> (raw) In-Reply-To: <20210714122753.76021-1-zhuangyi1@huawei.com> Yi Zhuang <zhuangyi1@huawei.com> a écrit : > Since snprintf() returns the possible output size instead of the > actual output size, the available flash_msg length returned by > get_validate_flash_msg may exceed the given buffer limit when > simple_read_from_buffer calls copy_to_user > > Reported-by: kernel test robot <lkp@intel.com> > Fixes: a94a14720eaf5 powerpc/rtas_flash: Fix validate_flash buffer > overflow issue > Signed-off-by: Yi Zhuang <zhuangyi1@huawei.com> > --- > arch/powerpc/kernel/rtas_flash.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kernel/rtas_flash.c > b/arch/powerpc/kernel/rtas_flash.c > index a99179d83538..062f0724c2ff 100644 > --- a/arch/powerpc/kernel/rtas_flash.c > +++ b/arch/powerpc/kernel/rtas_flash.c > @@ -470,9 +470,14 @@ static int get_validate_flash_msg(struct > rtas_validate_flash_t *args_buf, > if (args_buf->status >= VALIDATE_TMP_UPDATE) { > n = sprintf(msg, "%d\n", args_buf->update_results); > if ((args_buf->update_results >= VALIDATE_CUR_UNKNOWN) || > - (args_buf->update_results == VALIDATE_TMP_UPDATE)) > + (args_buf->update_results == VALIDATE_TMP_UPDATE)) { > n += snprintf(msg + n, msglen - n, "%s\n", > args_buf->buf); > + if (n >= msglen) { n cannot be greater than msglen > + n = msglen; > + printk(KERN_ERR "FLASH: msg too long.\n"); > + } > + } > } else { > n = sprintf(msg, "%d\n", args_buf->status); > } > -- > 2.26.0.106.g9fadedd
next prev parent reply other threads:[~2021-07-14 16:47 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-14 12:27 [PATCH v2] powerpc/rtas_flash: fix a potential buffer overflow Yi Zhuang 2021-07-14 12:27 ` Yi Zhuang 2021-07-14 16:52 ` Christophe Leroy [this message] 2021-07-14 16:52 ` Christophe Leroy
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