From: Mikulas Patocka mpatocka@redhat.com
[ Upstream commit 932aba1e169090357a77af18850a10c256b50819 ]
struct stat (defined in arch/x86/include/uapi/asm/stat.h) has 32-bit st_dev and st_rdev; struct compat_stat (defined in arch/x86/include/asm/compat.h) has 16-bit st_dev and st_rdev followed by a 16-bit padding.
This patch fixes struct compat_stat to match struct stat.
[ Historical note: the old x86 'struct stat' did have that 16-bit field that the compat layer had kept around, but it was changes back in 2003 by "struct stat - support larger dev_t":
https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=...
and back in those days, the x86_64 port was still new, and separate from the i386 code, and had already picked up the old version with a 16-bit st_dev field ]
Note that we can't change compat_dev_t because it is used by compat_loop_info.
Also, if the st_dev and st_rdev values are 32-bit, we don't have to use old_valid_dev to test if the value fits into them. This fixes -EOVERFLOW on filesystems that are on NVMe because NVMe uses the major number 259.
Signed-off-by: Mikulas Patocka mpatocka@redhat.com Cc: Andreas Schwab schwab@linux-m68k.org Cc: Matthew Wilcox willy@infradead.org Cc: Christoph Hellwig hch@infradead.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/include/asm/compat.h | 6 ++---- fs/stat.c | 19 ++++++++++--------- 2 files changed, 12 insertions(+), 13 deletions(-)
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index 2cbd75dd2fd3..ea142936bf11 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -57,15 +57,13 @@ struct compat_timeval { };
struct compat_stat { - compat_dev_t st_dev; - u16 __pad1; + u32 st_dev; compat_ino_t st_ino; compat_mode_t st_mode; compat_nlink_t st_nlink; __compat_uid_t st_uid; __compat_gid_t st_gid; - compat_dev_t st_rdev; - u16 __pad2; + u32 st_rdev; u32 st_size; u32 st_blksize; u32 st_blocks; diff --git a/fs/stat.c b/fs/stat.c index 873785dae022..0fda4b6b8fb2 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -286,9 +286,6 @@ SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, stat # define choose_32_64(a,b) b #endif
-#define valid_dev(x) choose_32_64(old_valid_dev(x),true) -#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x) - #ifndef INIT_STRUCT_STAT_PADDING # define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st)) #endif @@ -297,7 +294,9 @@ static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) { struct stat tmp;
- if (!valid_dev(stat->dev) || !valid_dev(stat->rdev)) + if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev)) + return -EOVERFLOW; + if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev)) return -EOVERFLOW; #if BITS_PER_LONG == 32 if (stat->size > MAX_NON_LFS) @@ -305,7 +304,7 @@ static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) #endif
INIT_STRUCT_STAT_PADDING(tmp); - tmp.st_dev = encode_dev(stat->dev); + tmp.st_dev = new_encode_dev(stat->dev); tmp.st_ino = stat->ino; if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) return -EOVERFLOW; @@ -315,7 +314,7 @@ static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) return -EOVERFLOW; SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); - tmp.st_rdev = encode_dev(stat->rdev); + tmp.st_rdev = new_encode_dev(stat->rdev); tmp.st_size = stat->size; tmp.st_atime = stat->atime.tv_sec; tmp.st_mtime = stat->mtime.tv_sec; @@ -582,11 +581,13 @@ static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf) { struct compat_stat tmp;
- if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev)) + if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev)) + return -EOVERFLOW; + if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev)) return -EOVERFLOW;
memset(&tmp, 0, sizeof(tmp)); - tmp.st_dev = old_encode_dev(stat->dev); + tmp.st_dev = new_encode_dev(stat->dev); tmp.st_ino = stat->ino; if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) return -EOVERFLOW; @@ -596,7 +597,7 @@ static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf) return -EOVERFLOW; SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); - tmp.st_rdev = old_encode_dev(stat->rdev); + tmp.st_rdev = new_encode_dev(stat->rdev); if ((u64) stat->size > MAX_NON_LFS) return -EOVERFLOW; tmp.st_size = stat->size;