Messages in this thread Patch in this message | | | Date | Sat, 23 Sep 2006 18:20:56 +0100 | From | Al Viro <> | Subject | [PATCH] briq_panel: read() and write() get __user pointers, damnit |
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annotated, fixed a roothole in ->write(). Dereferencing user-supplied pointer is a Bad Idea(tm)...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- drivers/char/briq_panel.c | 17 ++++++++++------- 1 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/drivers/char/briq_panel.c b/drivers/char/briq_panel.c index caae795..b8c2225 100644 --- a/drivers/char/briq_panel.c +++ b/drivers/char/briq_panel.c @@ -87,7 +87,7 @@ static int briq_panel_release(struct ino return 0; } -static ssize_t briq_panel_read(struct file *file, char *buf, size_t count, +static ssize_t briq_panel_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { unsigned short c; @@ -135,7 +135,7 @@ static void scroll_vfd( void ) vfd_cursor = 20; } -static ssize_t briq_panel_write(struct file *file, const char *buf, size_t len, +static ssize_t briq_panel_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos) { size_t indx = len; @@ -150,19 +150,22 @@ #endif return -EBUSY; for (;;) { + char c; if (!indx) break; + if (get_user(c, buf)) + return -EFAULT; if (esc) { - set_led(*buf); + set_led(c); esc = 0; - } else if (*buf == 27) { + } else if (c == 27) { esc = 1; - } else if (*buf == 12) { + } else if (c == 12) { /* do a form feed */ for (i=0; i<40; i++) vfd[i] = ' '; vfd_cursor = 0; - } else if (*buf == 10) { + } else if (c == 10) { if (vfd_cursor < 20) vfd_cursor = 20; else if (vfd_cursor < 40) @@ -175,7 +178,7 @@ #endif /* just a character */ if (vfd_cursor > 39) scroll_vfd(); - vfd[vfd_cursor++] = *buf; + vfd[vfd_cursor++] = c; } indx--; buf++; -- 1.4.2.GIT - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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