| From | Jiri Slaby <> | Subject | [PATCH 3.12 012/176] powerpc: Fix bad NULL pointer check in udbg_uart_getc_poll() | Date | Wed, 28 Jan 2015 15:27:22 +0100 |
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From: Anton Blanchard <anton@samba.org>
3.12-stable review patch. If anyone has any objections, please let me know.
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commit cd32e2dcc9de6c27ecbbfc0e2079fb64b42bad5f upstream.
We have some code in udbg_uart_getc_poll() that tries to protect against a NULL udbg_uart_in, but gets it all wrong.
Found with the LLVM static analyzer (scan-build).
Fixes: 309257484cc1 ("powerpc: Cleanup udbg_16550 and add support for LPC PIO-only UARTs") Signed-off-by: Anton Blanchard <anton@samba.org> [mpe: Add some newlines for readability while we're here] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- arch/powerpc/kernel/udbg_16550.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c index 75702e207b29..f7089fcfaa5d 100644 --- a/arch/powerpc/kernel/udbg_16550.c +++ b/arch/powerpc/kernel/udbg_16550.c @@ -69,8 +69,12 @@ static void udbg_uart_putc(char c) static int udbg_uart_getc_poll(void) { - if (!udbg_uart_in || !(udbg_uart_in(UART_LSR) & LSR_DR)) + if (!udbg_uart_in) + return -1; + + if (!(udbg_uart_in(UART_LSR) & LSR_DR)) return udbg_uart_in(UART_RBR); + return -1; } -- 2.2.2
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