This is a note to let you know that I've just added the patch titled staging/lustre/lov: remove set_fs() call from lov_getstripe() to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: staging-lustre-lov-remove-set_fs-call-from-lov_getstripe.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 0a33252e060e97ed3fbdcec9517672f1e91aaef3 Mon Sep 17 00:00:00 2001 From: Oleg Drokin <green@xxxxxxxxxxxxxx> Date: Fri, 26 May 2017 23:40:33 -0400 Subject: staging/lustre/lov: remove set_fs() call from lov_getstripe() From: Oleg Drokin <green@xxxxxxxxxxxxxx> commit 0a33252e060e97ed3fbdcec9517672f1e91aaef3 upstream. lov_getstripe() calls set_fs(KERNEL_DS) so that it can handle a struct lov_user_md pointer from user- or kernel-space. This changes the behavior of copy_from_user() on SPARC and may result in a misaligned access exception which in turn oopses the kernel. In fact the relevant argument to lov_getstripe() is never called with a kernel-space pointer and so changing the address limits is unnecessary and so we remove the calls to save, set, and restore the address limits. Signed-off-by: John L. Hammond <john.hammond@xxxxxxxxx> Reviewed-on: http://review.whamcloud.com/6150 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3221 Reviewed-by: Andreas Dilger <andreas.dilger@xxxxxxxxx> Reviewed-by: Li Wei <wei.g.li@xxxxxxxxx> Signed-off-by: Oleg Drokin <green@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/staging/lustre/lustre/lov/lov_pack.c | 9 --------- 1 file changed, 9 deletions(-) --- a/drivers/staging/lustre/lustre/lov/lov_pack.c +++ b/drivers/staging/lustre/lustre/lov/lov_pack.c @@ -420,18 +420,10 @@ int lov_getstripe(struct obd_export *exp struct lov_mds_md *lmmk = NULL; int rc, lmm_size; int lum_size; - mm_segment_t seg; if (!lsm) return -ENODATA; - /* - * "Switch to kernel segment" to allow copying from kernel space by - * copy_{to,from}_user(). - */ - seg = get_fs(); - set_fs(KERNEL_DS); - /* we only need the header part from user space to get lmm_magic and * lmm_stripe_count, (the header part is common to v1 and v3) */ lum_size = sizeof(struct lov_user_md_v1); @@ -507,6 +499,5 @@ int lov_getstripe(struct obd_export *exp obd_free_diskmd(exp, &lmmk); out_set: - set_fs(seg); return rc; } Patches currently in stable-queue which might be from green@xxxxxxxxxxxxxx are queue-3.18/staging-lustre-lov-remove-set_fs-call-from-lov_getstripe.patch