The msgsnd and msgrcv system calls use size_t to represent the size of the message being transferred. POSIX states that values of msgsz greater than SSIZE_MAX cause the result to be implementation-defined. On Linux, this equates to returning -EINVAL if (long) msgsz < 0. For compat tasks where !CONFIG_ARCH_WANT_OLD_COMPAT_IPC and compat_size_t is smaller than size_t, negative size values passed from userspace will be interpreted as positive values by do_msg{rcv,snd} and will fail to exit early with -EINVAL. This patch changes the compat prototypes for msg{rcv,snd} so that the message size is represented as a compat_ssize_t, which we cast to the native ssize_t type for the core IPC code. Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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.. | ||
Makefile | ||
compat.c | ||
compat_mq.c | ||
ipc_sysctl.c | ||
ipcns_notifier.c | ||
mq_sysctl.c | ||
mqueue.c | ||
msg.c | ||
msgutil.c | ||
namespace.c | ||
sem.c | ||
shm.c | ||
syscall.c | ||
util.c | ||
util.h |