linux/fs/isofs/inode.c

1636 lines
41 KiB

2011-01-07 17:49:49 +11:00
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 15:29:47 +03:00
isofs: avoid memory leak in iocharset A memleak was found as below: unreferenced object 0xffff0000d10164d8 (size 8): comm "pool-udisksd", pid 108217, jiffies 4295408555 hex dump (first 8 bytes): 75 74 66 38 00 cc cc cc utf8.... backtrace (crc de430d31): [<ffff800081046e6c>] kmemleak_alloc+0xb8/0xc8 [<ffff8000803e6c3c>] __kmalloc_node_track_caller_noprof+0x380/0x474 [<ffff800080363b74>] kstrdup+0x70/0xfc [<ffff80007bb3c6a4>] isofs_parse_param+0x228/0x2c0 [isofs] [<ffff8000804d7f68>] vfs_parse_fs_param+0xf4/0x164 [<ffff8000804d8064>] vfs_parse_fs_string+0x8c/0xd4 [<ffff8000804d815c>] vfs_parse_monolithic_sep+0xb0/0xfc [<ffff8000804d81d8>] generic_parse_monolithic+0x30/0x3c [<ffff8000804d8bfc>] parse_monolithic_mount_data+0x40/0x4c [<ffff8000804b6a64>] path_mount+0x6c4/0x9ec [<ffff8000804b6e38>] do_mount+0xac/0xc4 [<ffff8000804b7494>] __arm64_sys_mount+0x16c/0x2b0 [<ffff80008002b8dc>] invoke_syscall+0x7c/0x104 [<ffff80008002ba44>] el0_svc_common.constprop.1+0xe0/0x104 [<ffff80008002ba94>] do_el0_svc+0x2c/0x38 [<ffff800081041108>] el0_svc+0x3c/0x1b8 The opt->iocharset is freed inside the isofs_fill_super function, But there may be situations where it's not possible to enter this function. For example, in the get_tree_bdev_flags function,when encountering the situation where "Can't mount, would change RO state," In such a case, isofs_fill_super will not have the opportunity to be called,which means that opt->iocharset will not have the chance to be freed,ultimately leading to a memory leak. Let's move the memory freeing of opt->iocharset into isofs_free_fc function. Fixes: 1b17a46c9243 ("isofs: convert isofs to use the new mount API") Signed-off-by: Hao Ge <gehao@kylinos.cn> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20241106082841.51773-1-hao.ge@linux.dev
2024-11-06 16:28:41 +08:00
fs: Limit sys_mount to only request filesystem modules. Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Kees Cook <keescook@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-02 19:39:14 -08:00