From 9dfa7bba35ac08a63565d58c454dccb7e1bb0a08 Mon Sep 17 00:00:00 2001 From: Michael Schmitz Date: Sun, 30 Apr 2017 19:49:21 +1200 Subject: fix race in drivers/char/random.c:get_reg() get_reg() can be reentered on architectures with prioritized interrupts (m68k in this case), causing f->reg_index to be incremented after the range check. Out of bounds memory access past the pt_regs struct results. This will go mostly undetected unless access is beyond end of memory. Prevent the race by disabling interrupts in get_reg(). Tested on m68k (Atari Falcon, and ARAnyM emulator). Kudos to Geert Uytterhoeven for helping to trace this race. Signed-off-by: Michael Schmitz Signed-off-by: Theodore Ts'o --- drivers/char/random.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/random.c b/drivers/char/random.c index 0ab024918907..a561f0c2f428 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1097,12 +1097,16 @@ static void add_interrupt_bench(cycles_t start) static __u32 get_reg(struct fast_pool *f, struct pt_regs *regs) { __u32 *ptr = (__u32 *) regs; + unsigned long flags; if (regs == NULL) return 0; + local_irq_save(flags); if (f->reg_idx >= sizeof(struct pt_regs) / sizeof(__u32)) f->reg_idx = 0; - return *(ptr + f->reg_idx++); + ptr += f->reg_idx++; + local_irq_restore(flags); + return *ptr; } void add_interrupt_randomness(int irq, int irq_flags) -- cgit v1.2.3-58-ga151 From ff5a20169b98d84ad8d7f99f27c5ebbb008204d6 Mon Sep 17 00:00:00 2001 From: Nicolas Iooss Date: Fri, 2 Jun 2017 14:46:28 -0700 Subject: pcmcia: remove left-over %Z format Commit 5b5e0928f742 ("lib/vsprintf.c: remove %Z support") removed some usages of format %Z but forgot "%.2Zx". This makes clang 4.0 reports a -Wformat-extra-args warning because it does not know about %Z. Replace %Z with %z. Link: http://lkml.kernel.org/r/20170520090946.22562-1-nicolas.iooss_linux@m4x.org Signed-off-by: Nicolas Iooss Cc: Harald Welte Cc: Alexey Dobriyan Cc: [4.11+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/pcmcia/cm4040_cs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/pcmcia/cm4040_cs.c b/drivers/char/pcmcia/cm4040_cs.c index d4dbd8d8e524..382c864814d9 100644 --- a/drivers/char/pcmcia/cm4040_cs.c +++ b/drivers/char/pcmcia/cm4040_cs.c @@ -374,7 +374,7 @@ static ssize_t cm4040_write(struct file *filp, const char __user *buf, rc = write_sync_reg(SCR_HOST_TO_READER_START, dev); if (rc <= 0) { - DEBUGP(5, dev, "write_sync_reg c=%.2Zx\n", rc); + DEBUGP(5, dev, "write_sync_reg c=%.2zx\n", rc); DEBUGP(2, dev, "<- cm4040_write (failed)\n"); if (rc == -ERESTARTSYS) return rc; @@ -387,7 +387,7 @@ static ssize_t cm4040_write(struct file *filp, const char __user *buf, for (i = 0; i < bytes_to_write; i++) { rc = wait_for_bulk_out_ready(dev); if (rc <= 0) { - DEBUGP(5, dev, "wait_for_bulk_out_ready rc=%.2Zx\n", + DEBUGP(5, dev, "wait_for_bulk_out_ready rc=%.2zx\n", rc); DEBUGP(2, dev, "<- cm4040_write (failed)\n"); if (rc == -ERESTARTSYS) @@ -403,7 +403,7 @@ static ssize_t cm4040_write(struct file *filp, const char __user *buf, rc = write_sync_reg(SCR_HOST_TO_READER_DONE, dev); if (rc <= 0) { - DEBUGP(5, dev, "write_sync_reg c=%.2Zx\n", rc); + DEBUGP(5, dev, "write_sync_reg c=%.2zx\n", rc); DEBUGP(2, dev, "<- cm4040_write (failed)\n"); if (rc == -ERESTARTSYS) return rc; -- cgit v1.2.3-58-ga151