On 5/31/2018 2:28 AM, CHANDAN VN wrote: > From: "sireesha.t" <sireesha.t@xxxxxxxxxxx> > > Leak is caused because smack_inode_getsecurity() is allocating memory > using kstrdup(). Though the security_release_secctx() is called, it > would not free the allocated memory. Calling security_release_secctx is > not relevant for this scenario as inode_getsecurity() does not provide a > "secctx". > > Similar fix has been mainlined: > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?id=57e7ba04d422c3d41c8426380303ec9b7533ded9 > > The fix is to replace the security_release_secctx() with a kfree() > > Below is the KMEMLEAK dump: > unreferenced object 0xffffffc025e11c80 (size 64): > comm "systemd-tmpfile", pid 2452, jiffies 4294894464 (age 235587.492s) > hex dump (first 32 bytes): > 53 79 73 74 65 6d 3a 3a 53 68 61 72 65 64 00 00 System::Shared.. > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<ffffff80081be770>] __save_stack_trace+0x28/0x34 > [<ffffff80081bedb8>] create_object+0x130/0x25c > [<ffffff80088c82f8>] kmemleak_alloc+0x30/0x5c > [<ffffff80081b3ef0>] __kmalloc_track_caller+0x1cc/0x2a8 > [<ffffff800818673c>] kstrdup+0x3c/0x6c > [<ffffff80082d78b0>] smack_inode_getsecurity+0xcc/0xec > [<ffffff80082d78f4>] smack_inode_getsecctx+0x24/0x44 > [<ffffff80082d5ea0>] security_inode_getsecctx+0x50/0x70 > [<ffffff800823bbcc>] kernfs_security_xattr_set+0x74/0xe0 > [<ffffff80081eafec>] __vfs_setxattr+0x74/0x90 > [<ffffff80081eb088>] __vfs_setxattr_noperm+0x80/0x1ac > [<ffffff80081eb238>] vfs_setxattr+0x84/0xac > [<ffffff80081eb374>] setxattr+0x114/0x178 > [<ffffff80081eb44c>] path_setxattr+0x74/0xb8 > [<ffffff80081ebdcc>] SyS_lsetxattr+0x10/0x1c > [<ffffff800808310c>] __sys_trace_return+0x0/0x4 > > Signed-off-by: sireesha.t <sireesha.t@xxxxxxxxxxx> > Signed-off-by: CHANDAN VN <chandan.vn@xxxxxxxxxxx> Why not: static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) { - int len = 0; - len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true); + int len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, false); if (len < 0) return len; > --- > fs/kernfs/inode.c | 3 ++- > fs/nfsd/nfs4xdr.c | 2 +- > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c > index a343039..53befb8 100644 > --- a/fs/kernfs/inode.c > +++ b/fs/kernfs/inode.c > @@ -369,7 +369,8 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler, > mutex_unlock(&kernfs_mutex); > > if (secdata) > - security_release_secctx(secdata, secdata_len); > + kfree(secdata); > + > return error; > } > > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c > index aaa88c1..1e0dbe9 100644 > --- a/fs/nfsd/nfs4xdr.c > +++ b/fs/nfsd/nfs4xdr.c > @@ -2911,7 +2911,7 @@ static int get_parent_attributes(struct svc_export *exp, struct kstat *stat) > out: > #ifdef CONFIG_NFSD_V4_SECURITY_LABEL > if (context) > - security_release_secctx(context, contextlen); > + kfree(context); > #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */ > kfree(acl); > if (tempfh) { -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
