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| author |  Lee Jones <lee@kernel.org>
| 2023-12-13 16:42:32 +0000 |
|---|---|---|
| committer |  Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| 2023-12-15 13:55:29 +0100 |
| commit | 60034e0aedf507888c4a880f57011bb7f5d7700c (patch) | |
| tree | 5be69649d730c4c0bd212769b02347bebad7bdf6 /drivers/usb/gadget | |
| parent | usb: gadget: f_uac1: Replace snprintf() with the safer scnprintf() variant (diff) | |
| download | linux-60034e0aedf507888c4a880f57011bb7f5d7700c.tar.gz linux-60034e0aedf507888c4a880f57011bb7f5d7700c.tar.bz2 linux-60034e0aedf507888c4a880f57011bb7f5d7700c.zip | |
usb: gadget: f_uac2: Replace snprintf() with the safer scnprintf() variant
There is a general misunderstanding amongst engineers that {v}snprintf()
returns the length of the data *actually* encoded into the destination
array. However, as per the C99 standard {v}snprintf() really returns
the length of the data that *would have been* written if there were
enough space for it. This misunderstanding has led to buffer-overruns
in the past. It's generally considered safer to use the {v}scnprintf()
variants in their place (or even sprintf() in simple cases). So let's
do that.
Link: https://lwn.net/Articles/69419/
Link: https://github.com/KSPP/linux/issues/105
Cc: James Gruber <jimmyjgruber@gmail.com>
Cc: Yadwinder Singh <yadi.brar01@gmail.com>
Cc: Jaswinder Singh <jaswinder.singh@linaro.org>
Cc: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20231213164246.1021885-4-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/gadget')
| -rw-r--r-- | drivers/usb/gadget/function/f_uac2.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c index f9a0f07a7476..383f6854cfec 100644 --- a/drivers/usb/gadget/function/f_uac2.c +++ b/drivers/usb/gadget/function/f_uac2.c @@ -2045,7 +2045,7 @@ static ssize_t f_uac2_opts_##name##_show(struct config_item *item, \ int result; \ \ mutex_lock(&opts->lock); \ - result = snprintf(page, sizeof(opts->name), "%s", opts->name); \ + result = scnprintf(page, sizeof(opts->name), "%s", opts->name); \ mutex_unlock(&opts->lock); \ \ return result; \ @@ -2063,7 +2063,7 @@ static ssize_t f_uac2_opts_##name##_store(struct config_item *item, \ goto end; \ } \ \ - ret = snprintf(opts->name, min(sizeof(opts->name), len), \ + ret = scnprintf(opts->name, min(sizeof(opts->name), len), \ "%s", page); \ \ end: \ @@ -2187,7 +2187,7 @@ static struct usb_function_instance *afunc_alloc_inst(void) opts->req_number = UAC2_DEF_REQ_NUM; opts->fb_max = FBACK_FAST_MAX; - snprintf(opts->function_name, sizeof(opts->function_name), "Source/Sink"); + scnprintf(opts->function_name, sizeof(opts->function_name), "Source/Sink"); opts->p_terminal_type = UAC2_DEF_P_TERM_TYPE; opts->c_terminal_type = UAC2_DEF_C_TERM_TYPE; |