From: Nick Bowler nbowler@draconx.ca
[ Upstream commit 7ca860e3c1a74ad6bd8949364073ef1044cad758 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- fs/xfs/xfs_ioctl32.c | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-)
diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c index 8f18756ee405e..6b7ed221726db 100644 --- a/fs/xfs/xfs_ioctl32.c +++ b/fs/xfs/xfs_ioctl32.c @@ -251,6 +251,32 @@ 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) */
@@ -282,15 +308,15 @@ 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;