Messages in this thread Patch in this message | | | From | Yi Zhuang <> | Subject | [PATCH] powerpc/rtas_flash: fix a potential buffer overflow | Date | Wed, 14 Jul 2021 09:16:08 +0800 |
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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
Signed-off-by: Yi Zhuang <zhuangyi1@huawei.com> --- arch/powerpc/kernel/rtas_flash.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c index a99179d83538..4aa6bad28556 100644 --- a/arch/powerpc/kernel/rtas_flash.c +++ b/arch/powerpc/kernel/rtas_flash.c @@ -473,6 +473,10 @@ static int get_validate_flash_msg(struct rtas_validate_flash_t *args_buf, (args_buf->update_results == VALIDATE_TMP_UPDATE)) n += snprintf(msg + n, msglen - n, "%s\n", args_buf->buf); + if (n >= 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
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