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authorMikulas Patocka <mpatocka@redhat.com>2022-04-12 05:41:00 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-12 13:35:08 -1000
commit932aba1e169090357a77af18850a10c256b50819 (patch)
tree1fc1a9af62db9dccf21e64412b7a75f3f017d201 /fs/stat.c
parent7281a59ce3a584ed7379bbdcd06a2008c47c3e5c (diff)
stat: fix inconsistency between struct stat and struct compat_stat
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=e95b2065677fe32512a597a79db94b77b90c968d 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>
Diffstat (limited to 'fs/stat.c')
-rw-r--r--fs/stat.c19
1 files changed, 10 insertions, 9 deletions
diff --git a/fs/stat.c b/fs/stat.c
index 7f734be0e57e..5c2c94464e8b 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -348,9 +348,6 @@ 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
@@ -359,7 +356,9 @@ 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)
@@ -367,7 +366,7 @@ 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;
@@ -377,7 +376,7 @@ 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;
@@ -665,11 +664,13 @@ 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;
@@ -679,7 +680,7 @@ 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;