tree 8a3be5560a83e11bc07774673eb180354c31f86a
parent a38fd8748464831584a19438cbb3082b5a2dab15
author Al Viro <viro@zeniv.linux.org.uk> 1616695954 -0400
committer Al Viro <viro@zeniv.linux.org.uk> 1616713062 -0400

hostfs: fix memory handling in follow_link()

1) argument should not be freed in any case - the caller already has
it as ->s_fs_info (and uses it a lot afterwards)
2) allocate readlink buffer with kmalloc() - the caller has no way
to tell if it's got that (on absolute symlink) or a result of
kasprintf().  Sure, for SLAB and SLUB kfree() works on results of
kmem_cache_alloc(), but that's not documented anywhere, might change
in the future *and* is already not true for SLOB.

Fixes: 52b209f7b848 ("get rid of hostfs_read_inode()")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>