6.5-stable review patch. If anyone has any objections, please let me know.
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From: Namjae Jeon linkinjeon@kernel.org
commit eebff19acaa35820cb09ce2ccb3d21bee2156ffb upstream.
slab out-of-bounds write is caused by that offsets is bigger than pntsd allocation size. This patch add the check to validate 3 offsets using allocation size.
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-22271 Cc: stable@vger.kernel.org Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/server/smbacl.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-)
--- a/fs/smb/server/smbacl.c +++ b/fs/smb/server/smbacl.c @@ -1107,6 +1107,7 @@ pass: struct smb_acl *pdacl; struct smb_sid *powner_sid = NULL, *pgroup_sid = NULL; int powner_sid_size = 0, pgroup_sid_size = 0, pntsd_size; + int pntsd_alloc_size;
if (parent_pntsd->osidoffset) { powner_sid = (struct smb_sid *)((char *)parent_pntsd + @@ -1119,9 +1120,10 @@ pass: pgroup_sid_size = 1 + 1 + 6 + (pgroup_sid->num_subauth * 4); }
- pntsd = kzalloc(sizeof(struct smb_ntsd) + powner_sid_size + - pgroup_sid_size + sizeof(struct smb_acl) + - nt_size, GFP_KERNEL); + pntsd_alloc_size = sizeof(struct smb_ntsd) + powner_sid_size + + pgroup_sid_size + sizeof(struct smb_acl) + nt_size; + + pntsd = kzalloc(pntsd_alloc_size, GFP_KERNEL); if (!pntsd) { rc = -ENOMEM; goto free_aces_base; @@ -1136,6 +1138,27 @@ pass: pntsd->gsidoffset = parent_pntsd->gsidoffset; pntsd->dacloffset = parent_pntsd->dacloffset;
+ if ((u64)le32_to_cpu(pntsd->osidoffset) + powner_sid_size > + pntsd_alloc_size) { + rc = -EINVAL; + kfree(pntsd); + goto free_aces_base; + } + + if ((u64)le32_to_cpu(pntsd->gsidoffset) + pgroup_sid_size > + pntsd_alloc_size) { + rc = -EINVAL; + kfree(pntsd); + goto free_aces_base; + } + + if ((u64)le32_to_cpu(pntsd->dacloffset) + sizeof(struct smb_acl) + nt_size > + pntsd_alloc_size) { + rc = -EINVAL; + kfree(pntsd); + goto free_aces_base; + } + if (pntsd->osidoffset) { struct smb_sid *owner_sid = (struct smb_sid *)((char *)pntsd + le32_to_cpu(pntsd->osidoffset));