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| author | Ahmad Fatoum <ahmad@a3f.at> | 2019-09-20 09:58:10 +0200 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2019-10-14 12:52:11 +0200 |
| commit | 3e51bdfd2c31e1f3bdb3a65f6480950ba360b8e6 (patch) | |
| tree | d59612e6bf9531d47c2bb6fd1da1bacb4d7731ff /common | |
| parent | d1210dc63f38e7e6d8147b44b3f6f9518c099306 (diff) | |
| download | barebox-3e51bdfd2c31e1f3bdb3a65f6480950ba360b8e6.tar.gz barebox-3e51bdfd2c31e1f3bdb3a65f6480950ba360b8e6.tar.xz | |
console: disallow opening for writing when no write method defined
Some consoles, like the input console (usually /dev/cs0), don't feature
a puts or putc callback. Trying to echo out of them would thus crash:
barebox@Embest MarS Board i.MX6Dual:/ echo -a /dev/cs0
prefetch abort
pc : [<00000004>] lr : [<4fd05071>]
WARNING: [<...>] (fops_write+0xd/0x10)
WARNING: [<...>] (devfs_write+0x21/0x2a)
WARNING: [<...>] (__write+0xcb/0xf0)
WARNING: [<...>] (write+0x2d/0x68)
WARNING: [<...>] (dputc+0x31/0x34)
WARNING: [<...>] (do_echo+0xcb/0x144)
Fix this by only allowing open(.., O_WRONLY) or open(..., O_RDWR) when
puts is defined. Consoles defining putc are covered by this as well as
those have putc-calling __console_puts assigned as their puts when they
are registered. Now echo -a /dev/cs0 would yield:
open: Operation not permitted
Signed-off-by: Ahmad Fatoum <ahmad@a3f.at>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'common')
| -rw-r--r-- | common/console.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/common/console.c b/common/console.c index d04aae58f9..e6e029848d 100644 --- a/common/console.c +++ b/common/console.c @@ -272,6 +272,9 @@ static int fops_open(struct cdev *cdev, unsigned long flags) { struct console_device *priv = cdev->priv; + if ((flags & (O_WRONLY | O_RDWR)) && !priv->puts ) + return -EPERM; + return console_open(priv); } |