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fanotify: Fix sys_fanotify_mark() on native x86-32

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  121b32a58a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments")

converted native x86-32 which take 64-bit arguments to use the
compat handlers to allow conversion to passing args via pt_regs.
sys_fanotify_mark() was however missed, as it has a general compat
handler. Add a config option that will use the syscall wrapper that
takes the split args for native 32-bit.

 [ bp: Fix typo in Kconfig help text. ]

Fixes: 121b32a58a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments")
Reported-by: Paweł Jasiak <pawel@jasiak.xyz>
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20201130223059.101286-1-brgerst@gmail.com
This commit is contained in:
Brian Gerst 2020-11-30 17:30:59 -05:00 committed by Borislav Petkov
parent 5c8fe583cc
commit 2ca408d9c7
4 changed files with 38 additions and 10 deletions
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6
arch/Kconfig
View File

@ -1105,6 +1105,12 @@ config HAVE_ARCH_PFN_VALID
config ARCH_SUPPORTS_DEBUG_PAGEALLOC
bool
config ARCH_SPLIT_ARG64
bool
help
If a 32-bit architecture requires 64-bit arguments to be split into
pairs of 32-bit arguments, select this option.
source "kernel/gcov/Kconfig"
source "scripts/gcc-plugins/Kconfig"

1
arch/x86/Kconfig
View File

@ -19,6 +19,7 @@ config X86_32
select KMAP_LOCAL
select MODULES_USE_ELF_REL
select OLD_SIGACTION
select ARCH_SPLIT_ARG64
config X86_64
def_bool y

17
fs/notify/fanotify/fanotify_user.c
View File

@ -1285,26 +1285,23 @@ fput_and_out:
return ret;
}
#ifndef CONFIG_ARCH_SPLIT_ARG64
SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags,
__u64, mask, int, dfd,
const char __user *, pathname)
{
return do_fanotify_mark(fanotify_fd, flags, mask, dfd, pathname);
}
#endif
#ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE6(fanotify_mark,
#if defined(CONFIG_ARCH_SPLIT_ARG64) || defined(CONFIG_COMPAT)
SYSCALL32_DEFINE6(fanotify_mark,
int, fanotify_fd, unsigned int, flags,
__u32, mask0, __u32, mask1, int, dfd,
SC_ARG64(mask), int, dfd,
const char __user *, pathname)
{
return do_fanotify_mark(fanotify_fd, flags,
#ifdef __BIG_ENDIAN
((__u64)mask0 << 32) | mask1,
#else
((__u64)mask1 << 32) | mask0,
#endif
dfd, pathname);
return do_fanotify_mark(fanotify_fd, flags, SC_VAL64(__u64, mask),
dfd, pathname);
}
#endif

24
include/linux/syscalls.h
View File

@ -251,6 +251,30 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
#endif /* __SYSCALL_DEFINEx */
/* For split 64-bit arguments on 32-bit architectures */
#ifdef __LITTLE_ENDIAN
#define SC_ARG64(name) u32, name##_lo, u32, name##_hi
#else
#define SC_ARG64(name) u32, name##_hi, u32, name##_lo
#endif
#define SC_VAL64(type, name) ((type) name##_hi << 32 | name##_lo)
#ifdef CONFIG_COMPAT
#define SYSCALL32_DEFINE1 COMPAT_SYSCALL_DEFINE1
#define SYSCALL32_DEFINE2 COMPAT_SYSCALL_DEFINE2
#define SYSCALL32_DEFINE3 COMPAT_SYSCALL_DEFINE3
#define SYSCALL32_DEFINE4 COMPAT_SYSCALL_DEFINE4
#define SYSCALL32_DEFINE5 COMPAT_SYSCALL_DEFINE5
#define SYSCALL32_DEFINE6 COMPAT_SYSCALL_DEFINE6
#else
#define SYSCALL32_DEFINE1 SYSCALL_DEFINE1
#define SYSCALL32_DEFINE2 SYSCALL_DEFINE2
#define SYSCALL32_DEFINE3 SYSCALL_DEFINE3
#define SYSCALL32_DEFINE4 SYSCALL_DEFINE4
#define SYSCALL32_DEFINE5 SYSCALL_DEFINE5
#define SYSCALL32_DEFINE6 SYSCALL_DEFINE6
#endif
/*
* Called before coming back to user-mode. Returning to user-mode with an
* address limit different than USER_DS can allow to overwrite kernel memory.