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| author | Randy Dunlap <rdunlap@xenotime.net> | 2006-03-08 16:46:08 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2006-03-08 16:46:08 -0800 |
| commit | 1efa3c05f8640c37ba89d54dfaa18504d21986ce (patch) | |
| tree | c777fd8a5fc44492971ac51f8299c4cbfb52f175 /fs | |
| parent | 2ec5e3a867d63d04932e11c6097f63760d9be3fe (diff) | |
| download | lwn-1efa3c05f8640c37ba89d54dfaa18504d21986ce.tar.gz lwn-1efa3c05f8640c37ba89d54dfaa18504d21986ce.zip | |
[NET] compat ifconf: fix limits
A recent change to compat. dev_ifconf() in fs/compat_ioctl.c
causes ifconf data to be truncated 1 entry too early when copying it
to userspace. The correct amount of data (length) is returned,
but the final entry is empty (zero, not filled in).
The for-loop 'i' check should use <= to allow the final struct
ifreq32 to be copied. I also used the ifconf-corruption program
in kernel bugzilla #4746 to make sure that this change does not
re-introduce the corruption.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/compat_ioctl.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c index 537ac70edfe5..c666769a875d 100644 --- a/fs/compat_ioctl.c +++ b/fs/compat_ioctl.c @@ -446,7 +446,7 @@ static int dev_ifconf(unsigned int fd, unsigned int cmd, unsigned long arg) ifr = ifc.ifc_req; ifr32 = compat_ptr(ifc32.ifcbuf); for (i = 0, j = 0; - i + sizeof (struct ifreq32) < ifc32.ifc_len && j < ifc.ifc_len; + i + sizeof (struct ifreq32) <= ifc32.ifc_len && j < ifc.ifc_len; i += sizeof (struct ifreq32), j += sizeof (struct ifreq)) { if (copy_in_user(ifr32, ifr, sizeof (struct ifreq32))) return -EFAULT; |