kernel.git/fs/nfs/flexfilelayout/flexfilelayout.c, branch linux-6.10.y

pNFS: rework pnfs_generic_pg_check_layout to check IO range

2024-05-21T12:34:15Z

All callers of pnfs_generic_pg_check_layout() also want to do a call to check that the layout's range covers the IO range. Merge the functionality of the pnfs_generic_pg_check_range() into that of pnfs_generic_pg_check_layout(). Signed-off-by: Olga Kornievskaia Reviewed-by: Benjamin Coddington Signed-off-by: Trond Myklebust

nfs: fix panic when nfs4_ff_layout_prepare_ds() fails

2024-03-16T16:41:45Z

We've been seeing the following panic in production BUG: kernel NULL pointer dereference, address: 0000000000000065 PGD 2f485f067 P4D 2f485f067 PUD 2cc5d8067 PMD 0 RIP: 0010:ff_layout_cancel_io+0x3a/0x90 [nfs_layout_flexfiles] Call Trace: ? __die+0x78/0xc0 ? page_fault_oops+0x286/0x380 ? __rpc_execute+0x2c3/0x470 [sunrpc] ? rpc_new_task+0x42/0x1c0 [sunrpc] ? exc_page_fault+0x5d/0x110 ? asm_exc_page_fault+0x22/0x30 ? ff_layout_free_layoutreturn+0x110/0x110 [nfs_layout_flexfiles] ? ff_layout_cancel_io+0x3a/0x90 [nfs_layout_flexfiles] ? ff_layout_cancel_io+0x6f/0x90 [nfs_layout_flexfiles] pnfs_mark_matching_lsegs_return+0x1b0/0x360 [nfsv4] pnfs_error_mark_layout_for_return+0x9e/0x110 [nfsv4] ? ff_layout_send_layouterror+0x50/0x160 [nfs_layout_flexfiles] nfs4_ff_layout_prepare_ds+0x11f/0x290 [nfs_layout_flexfiles] ff_layout_pg_init_write+0xf0/0x1f0 [nfs_layout_flexfiles] __nfs_pageio_add_request+0x154/0x6c0 [nfs] nfs_pageio_add_request+0x26b/0x380 [nfs] nfs_do_writepage+0x111/0x1e0 [nfs] nfs_writepages_callback+0xf/0x30 [nfs] write_cache_pages+0x17f/0x380 ? nfs_pageio_init_write+0x50/0x50 [nfs] ? nfs_writepages+0x6d/0x210 [nfs] ? nfs_writepages+0x6d/0x210 [nfs] nfs_writepages+0x125/0x210 [nfs] do_writepages+0x67/0x220 ? generic_perform_write+0x14b/0x210 filemap_fdatawrite_wbc+0x5b/0x80 file_write_and_wait_range+0x6d/0xc0 nfs_file_fsync+0x81/0x170 [nfs] ? nfs_file_mmap+0x60/0x60 [nfs] __x64_sys_fsync+0x53/0x90 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Inspecting the core with drgn I was able to pull this >>> prog.crashed_thread().stack_trace()[0] #0 at 0xffffffffa079657a (ff_layout_cancel_io+0x3a/0x84) in ff_layout_cancel_io at fs/nfs/flexfilelayout/flexfilelayout.c:2021:27 >>> prog.crashed_thread().stack_trace()[0]['idx'] (u32)1 >>> prog.crashed_thread().stack_trace()[0]['flseg'].mirror_array[1].mirror_ds (struct nfs4_ff_layout_ds *)0xffffffffffffffed This is clear from the stack trace, we call nfs4_ff_layout_prepare_ds() which could error out initializing the mirror_ds, and then we go to clean it all up and our check is only for if (!mirror->mirror_ds). This is inconsistent with the rest of the users of mirror_ds, which have if (IS_ERR_OR_NULL(mirror_ds)) to keep from tripping over this exact scenario. Fix this up in ff_layout_cancel_io() to make sure we don't panic when we get an error. I also spot checked all the other instances of checking mirror_ds and we appear to be doing the correct checks everywhere, only unconditionally dereferencing mirror_ds when we know it would be valid. Signed-off-by: Josef Bacik Fixes: b739a5bd9d9f ("NFSv4/flexfiles: Cancel I/O if the layout is recalled or revoked") Reviewed-by: Jeff Layton Signed-off-by: Trond Myklebust

pNFS/flexfiles: Check the layout validity in ff_layout_mirror_prepare_stats

2023-10-18T18:42:09Z

Ensure that we check the layout pointer and validity after dereferencing it in ff_layout_mirror_prepare_stats. Fixes: 08e2e5bc6c9a ("pNFS/flexfiles: Clean up layoutstats") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

NFS/pNFS: Report EINVAL errors from connect() to the server

2023-09-13T15:51:11Z

With IPv6, connect() can occasionally return EINVAL if a route is unavailable. If this happens during I/O to a data server, we want to report it using LAYOUTERROR as an inability to connect. Fixes: dd52128afdde ("NFSv4.1/pnfs Ensure flexfiles reports all connection related errors") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

cred: Do not default to init_cred in prepare_kernel_cred()

2022-11-01T17:04:52Z

A common exploit pattern for ROP attacks is to abuse prepare_kernel_cred() in order to construct escalated privileges[1]. Instead of providing a short-hand argument (NULL) to the "daemon" argument to indicate using init_cred as the base cred, require that "daemon" is always set to an actual task. Replace all existing callers that were passing NULL with &init_task. Future attacks will need to have sufficiently powerful read/write primitives to have found an appropriately privileged task and written it to the ROP stack as an argument to succeed, which is similarly difficult to the prior effort needed to escalate privileges before struct cred existed: locate the current cred and overwrite the uid member. This has the added benefit of meaning that prepare_kernel_cred() can no longer exceed the privileges of the init task, which may have changed from the original init_cred (e.g. dropping capabilities from the bounding set). [1] https://google.com/search?q=commit_creds(prepare_kernel_cred(0)) Cc: "Eric W. Biederman" Cc: David Howells Cc: "Rafael J. Wysocki" Cc: Steve French Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Namjae Jeon Cc: Trond Myklebust Cc: Anna Schumaker Cc: Chuck Lever Cc: Jeff Layton Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: "Michal Koutný" Cc: Peter Zijlstra Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Cc: linux-nfs@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook Acked-by: Luis Chamberlain Reviewed-by: Sergey Senozhatsky Acked-by: Russ Weight Acked-by: Greg Kroah-Hartman Acked-by: Paulo Alcantara (SUSE) Link: https://lore.kernel.org/r/20221026232943.never.775-kees@kernel.org

NFSv4/flexfiles: Cancel I/O if the layout is recalled or revoked

2022-10-06T13:52:09Z

If the layout is recalled or revoked, we want to cancel I/O as quickly as possible so that we can return the layout. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

NFSv4/pNFS: Always return layout stats on layout return for flexfiles

2022-10-03T15:26:37Z

We want to ensure that the server never misses the layout stats when we're closing the file, so that it knows whether or not to update its internal state. Otherwise, if we were racing with a layout stat, we might cause the server to invalidate its layout before the layout stat got processed. Fixes: 06946c6a3d8b ("pNFS/flexfiles: Only send layoutstats updates for mirrors that were updated") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

pNFS/flexfiles: Report RDMA connection errors to the server

2022-07-10T23:00:53Z

The RPC/RDMA driver will return -EPROTO and -ENODEV as connection errors under certain circumstances. Make sure that we handle them and report them to the server. If not, we can end up cycling forever in a LAYOUTGET/LAYOUTRETURN loop. Fixes: a12f996d3413 ("NFSv4/pNFS: Use connections to a DS that are all of the same protocol family") Cc: stable@vger.kernel.org # 5.11.x Signed-off-by: Trond Myklebust

pNFS/flexfiles: Ensure pNFS allocation modes are consistent with nfsiod

2022-03-22T19:52:56Z

Ensure that pNFS flexfile allocations in rpciod/nfsiod callbacks can fail in low memory mode, so that the threads don't block and loop forever. Signed-off-by: Trond Myklebust

NFSv4/flexfiles: Convert GFP_NOFS to GFP_KERNEL

2022-02-25T23:50:12Z

Assume that the higher layers will have set memalloc_nofs_save/restore as appropriate. Signed-off-by: Trond Myklebust