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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2020-04-03 07:20:51 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-01 12:35:21 +1000 |
| commit | 41cd780524674082b037e7c8461f90c5e42103f0 (patch) | |
| tree | eb705efdf71be777efedd2cd76e1f47d7cd753e2 /kernel/compat.c | |
| parent | 999a22890cb183b918e4372395d24426a755cef2 (diff) | |
| download | linux-41cd780524674082b037e7c8461f90c5e42103f0.tar.gz linux-41cd780524674082b037e7c8461f90c5e42103f0.tar.bz2 linux-41cd780524674082b037e7c8461f90c5e42103f0.zip | |
uaccess: Selectively open read or write user access
When opening user access to only perform reads, only open read access.
When opening user access to only perform writes, only open write
access.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2e73bc57125c2c6ab12a587586a4eed3a47105fc.1585898438.git.christophe.leroy@c-s.fr
Diffstat (limited to 'kernel/compat.c')
| -rw-r--r-- | kernel/compat.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/compat.c b/kernel/compat.c index 843dd17e6078..b8d2800bb4b7 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -199,7 +199,7 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); - if (!user_access_begin(umask, bitmap_size / 8)) + if (!user_read_access_begin(umask, bitmap_size / 8)) return -EFAULT; while (nr_compat_longs > 1) { @@ -211,11 +211,11 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, } if (nr_compat_longs) unsafe_get_user(*mask, umask++, Efault); - user_access_end(); + user_read_access_end(); return 0; Efault: - user_access_end(); + user_read_access_end(); return -EFAULT; } @@ -228,7 +228,7 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); - if (!user_access_begin(umask, bitmap_size / 8)) + if (!user_write_access_begin(umask, bitmap_size / 8)) return -EFAULT; while (nr_compat_longs > 1) { @@ -239,10 +239,10 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, } if (nr_compat_longs) unsafe_put_user((compat_ulong_t)*mask, umask++, Efault); - user_access_end(); + user_write_access_end(); return 0; Efault: - user_access_end(); + user_write_access_end(); return -EFAULT; } |