diff options
author | Nick Bowler <nbowler@draconx.ca> | 2018-12-17 20:35:27 +0300 |
---|---|---|
committer | Darrick J. Wong <darrick.wong@oracle.com> | 2018-12-18 21:55:20 +0300 |
commit | 7ca860e3c1a74ad6bd8949364073ef1044cad758 (patch) | |
tree | 1ca973be589423b562b186c0c3cb97e777d75df3 | |
parent | c456d64449efe37da50832b63d91652a85ea1d20 (diff) | |
download | linux-7ca860e3c1a74ad6bd8949364073ef1044cad758.tar.xz |
xfs: Fix bulkstat compat ioctls on x32 userspace.
The bulkstat family of ioctls are problematic on x32, because there is
a mixup of native 32-bit and 64-bit conventions. The xfs_fsop_bulkreq
struct contains pointers and 32-bit integers so that matches the native
32-bit layout, and that means the ioctl implementation goes into the
regular compat path on x32.
However, the 'ubuffer' member of that struct in turn refers to either
struct xfs_inogrp or xfs_bstat (or an array of these). On x32, those
structures match the native 64-bit layout. The compat implementation
writes out the 32-bit version of these structures. This is not the
expected format for x32 userspace, causing problems.
Fortunately the functions which actually output these xfs_inogrp and
xfs_bstat structures have an easy way to select which output format
is required, so we just need a little tweak to select the right format
on x32.
Signed-off-by: Nick Bowler <nbowler@draconx.ca>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
-rw-r--r-- | fs/xfs/xfs_ioctl32.c | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c index 4c34efcbf7e8..b044f7d36782 100644 --- a/fs/xfs/xfs_ioctl32.c +++ b/fs/xfs/xfs_ioctl32.c @@ -241,6 +241,32 @@ xfs_compat_ioc_bulkstat( int done; int error; + /* + * Output structure handling functions. Depending on the command, + * either the xfs_bstat and xfs_inogrp structures are written out + * to userpace memory via bulkreq.ubuffer. Normally the compat + * functions and structure size are the correct ones to use ... + */ + inumbers_fmt_pf inumbers_func = xfs_inumbers_fmt_compat; + bulkstat_one_pf bs_one_func = xfs_bulkstat_one_compat; + size_t bs_one_size = sizeof(struct compat_xfs_bstat); + +#ifdef CONFIG_X86_X32 + if (in_x32_syscall()) { + /* + * ... but on x32 the input xfs_fsop_bulkreq has pointers + * which must be handled in the "compat" (32-bit) way, while + * the xfs_bstat and xfs_inogrp structures follow native 64- + * bit layout convention. So adjust accordingly, otherwise + * the data written out in compat layout will not match what + * x32 userspace expects. + */ + inumbers_func = xfs_inumbers_fmt; + bs_one_func = xfs_bulkstat_one; + bs_one_size = sizeof(struct xfs_bstat); + } +#endif + /* done = 1 if there are more stats to get and if bulkstat */ /* should be called again (unused here, but used in dmapi) */ @@ -272,15 +298,15 @@ xfs_compat_ioc_bulkstat( if (cmd == XFS_IOC_FSINUMBERS_32) { error = xfs_inumbers(mp, &inlast, &count, - bulkreq.ubuffer, xfs_inumbers_fmt_compat); + bulkreq.ubuffer, inumbers_func); } else if (cmd == XFS_IOC_FSBULKSTAT_SINGLE_32) { int res; - error = xfs_bulkstat_one_compat(mp, inlast, bulkreq.ubuffer, - sizeof(compat_xfs_bstat_t), NULL, &res); + error = bs_one_func(mp, inlast, bulkreq.ubuffer, + bs_one_size, NULL, &res); } else if (cmd == XFS_IOC_FSBULKSTAT_32) { error = xfs_bulkstat(mp, &inlast, &count, - xfs_bulkstat_one_compat, sizeof(compat_xfs_bstat_t), + bs_one_func, bs_one_size, bulkreq.ubuffer, &done); } else error = -EINVAL; |