aboutsummaryrefslogtreecommitdiff
path: root/hw/9pfs
AgeCommit message (Collapse)Author
2018-05-029p: add trace event for v9fs_setattr()Greg Kurz
Don't print the tv_nsec part of atime and mtime, to stay below the 10 argument limit of trace events. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-02-199p: fix leak in synth_name_to_path()Marc-André Lureau
Leak found thanks to ASAN: Direct leak of 8 byte(s) in 1 object(s) allocated from: #0 0x55995789ac90 in __interceptor_malloc (/home/elmarco/src/qemu/build/x86_64-softmmu/qemu-system-x86_64+0x1510c90) #1 0x7f0a91190f0c in g_malloc /home/elmarco/src/gnome/glib/builddir/../glib/gmem.c:94 #2 0x5599580a281c in v9fs_path_copy /home/elmarco/src/qemu/hw/9pfs/9p.c:196:17 #3 0x559958f9ec5d in coroutine_trampoline /home/elmarco/src/qemu/util/coroutine-ucontext.c:116:9 #4 0x7f0a8766ebbf (/lib64/libc.so.6+0x50bbf) Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Signed-off-by: Greg Kurz <groug@kaod.org>
2018-02-199p: v9fs_path_copy() readabilityMarc-André Lureau
lhs/rhs doesn't tell much about how argument are handled, dst/src is and const arguments is clearer in my mind. Use g_memdup() while at it. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Signed-off-by: Greg Kurz <groug@kaod.org>
2018-02-09Move include qemu/option.h from qemu-common.h to actual usersMarkus Armbruster
qemu-common.h includes qemu/option.h, but most places that include the former don't actually need the latter. Drop the include, and add it to the places that actually need it. While there, drop superfluous includes of both headers, and separate #include from file comment with a blank line. This cleanup makes the number of objects depending on qemu/option.h drop from 4545 (out of 4743) to 284 in my "build everything" tree. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-20-armbru@redhat.com> [Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]
2018-02-09Include qapi/error.h exactly where neededMarkus Armbruster
This cleanup makes the number of objects depending on qapi/error.h drop from 1910 (out of 4743) to 1612 in my "build everything" tree. While there, separate #include from file comment with a blank line, and drop a useless comment on why qemu/osdep.h is included first. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-5-armbru@redhat.com> [Semantic conflict with commit 34e304e975 resolved, OSX breakage fixed]
2018-02-02tests: virtio-9p: add FLUSH operation testGreg Kurz
The idea is to send a victim request that will possibly block in the server and to send a flush request to cancel the victim request. This patch adds two test to verifiy that: - the server does not reply to a victim request that was actually cancelled - the server replies to the flush request after replying to the victim request if it could not cancel it 9p request cancellation reference: http://man.cat-v.org/plan_9/5/flush Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> (groug, change the test to only write a single byte to avoid any alignment or endianess consideration)
2018-02-01tests: virtio-9p: add WRITE operation testGreg Kurz
Trivial test of a successful write. Signed-off-by: Greg Kurz <groug@kaod.org> (groug, handle potential overflow when computing request size, add missing g_free(buf), backend handles one written byte at a time to validate the server doesn't do short-reads) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-02-01tests: virtio-9p: add LOPEN operation testGreg Kurz
Trivial test of a successful open. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-02-01tests: virtio-9p: use the synth backendGreg Kurz
The purpose of virtio-9p-test is to test the virtio-9p device, especially the 9p server state machine. We don't really care what fsdev backend we're using. Moreover, if we want to be able to test the flush request or a device reset with in-flights I/O, it is close to impossible to achieve with a physical backend because we cannot ask it reliably to put an I/O on hold at a specific point in time. Fortunately, we can do that with the synthetic backend, which allows to register callbacks on read/write accesses to a specific file. This will be used by a later patch to test the 9P flush request. The walk request test is converted to using the synth backend. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-02-019pfs: Correctly handle cancelled requestsKeno Fischer
# Background I was investigating spurious non-deterministic EINTR returns from various 9p file system operations in a Linux guest served from the qemu 9p server. ## EINTR, ERESTARTSYS and the linux kernel When a signal arrives that the Linux kernel needs to deliver to user-space while a given thread is blocked (in the 9p case waiting for a reply to its request in 9p_client_rpc -> wait_event_interruptible), it asks whatever driver is currently running to abort its current operation (in the 9p case causing the submission of a TFLUSH message) and return to user space. In these situations, the error message reported is generally ERESTARTSYS. If the userspace processes specified SA_RESTART, this means that the system call will get restarted upon completion of the signal handler delivery (assuming the signal handler doesn't modify the process state in complicated ways not relevant here). If SA_RESTART is not specified, ERESTARTSYS gets translated to EINTR and user space is expected to handle the restart itself. ## The 9p TFLUSH command The 9p TFLUSH commands requests that the server abort an ongoing operation. The man page [1] specifies: ``` If it recognizes oldtag as the tag of a pending transaction, it should abort any pending response and discard that tag. [...] When the client sends a Tflush, it must wait to receive the corresponding Rflush before reusing oldtag for subsequent messages. If a response to the flushed request is received before the Rflush, the client must honor the response as if it had not been flushed, since the completed request may signify a state change in the server ``` In particular, this means that the server must not send a reply with the orignal tag in response to the cancellation request, because the client is obligated to interpret such a reply as a coincidental reply to the original request. # The bug When qemu receives a TFlush request, it sets the `cancelled` flag on the relevant pdu. This flag is periodically checked, e.g. in `v9fs_co_name_to_path`, and if set, the operation is aborted and the error is set to EINTR. However, the server then violates the spec, by returning to the client an Rerror response, rather than discarding the message entirely. As a result, the client is required to assume that said Rerror response is a result of the original request, not a result of the cancellation and thus passes the EINTR error back to user space. This is not the worst thing it could do, however as discussed above, the correct error code would have been ERESTARTSYS, such that user space programs with SA_RESTART set get correctly restarted upon completion of the signal handler. Instead, such programs get spurious EINTR results that they were not expecting to handle. It should be noted that there are plenty of user space programs that do not set SA_RESTART and do not correctly handle EINTR either. However, that is then a userspace bug. It should also be noted that this bug has been mitigated by a recent commit to the Linux kernel [2], which essentially prevents the kernel from sending Tflush requests unless the process is about to die (in which case the process likely doesn't care about the response). Nevertheless, for older kernels and to comply with the spec, I believe this change is beneficial. # Implementation The fix is fairly simple, just skipping notification of a reply if the pdu was previously cancelled. We do however, also notify the transport layer that we're doing this, so it can clean up any resources it may be holding. I also added a new trace event to distinguish operations that caused an error reply from those that were cancelled. One complication is that we only omit sending the message on EINTR errors in order to avoid confusing the rest of the code (which may assume that a client knows about a fid if it sucessfully passed it off to pud_complete without checking for cancellation status). This does mean that if the server acts upon the cancellation flag, it always needs to set err to EINTR. I believe this is true of the current code. [1] https://9fans.github.io/plan9port/man/man9/flush.html [2] https://github.com/torvalds/linux/commit/9523feac272ccad2ad8186ba4fcc891 Signed-off-by: Keno Fischer <keno@juliacomputing.com> Reviewed-by: Greg Kurz <groug@kaod.org> [groug, send a zero-sized reply instead of detaching the buffer] Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2018-02-019pfs: drop v9fs_register_transport()Greg Kurz
No good reasons to do this outside of v9fs_device_realize_common(). Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2018-01-089pfs: deprecate handle backendGreg Kurz
This backend raise some concerns: - doesn't support symlinks - fails +100 tests in the PJD POSIX file system test suite [1] - requires the QEMU process to run with the CAP_DAC_READ_SEARCH capability, which isn't recommended for security reasons This backend should not be used and wil be removed. The 'local' backend is the recommended alternative. [1] https://www.tuxera.com/community/posix-test-suite/ Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2018-01-08fsdev: improve error handling of backend initGreg Kurz
This patch changes some error messages in the backend init code and convert backends to propagate QEMU Error objects instead of calling error_report(). One notable improvement is that the local backend now provides a more detailed error report when it fails to open the shared directory. Signed-off-by: Greg Kurz <groug@kaod.org>
2018-01-08fsdev: improve error handling of backend opts parsingGreg Kurz
This patch changes some error messages in the backend opts parsing code and convert backends to propagate QEMU Error objects instead of calling error_report(). Signed-off-by: Greg Kurz <groug@kaod.org>
2018-01-089pfs: make pdu_marshal() and pdu_unmarshal() static functionsGreg Kurz
They're only used by the 9p core code. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2018-01-089pfs: fix error path in pdu_submit()Greg Kurz
If we receive an unsupported request id, we first decide to return -ENOTSUPP to the client, but since the request id causes is_read_only_op() to return false, we change the error to be -EROFS if the fsdev is read-only. This doesn't make sense since we don't know what the client asked for. This patch ensures that -EROFS can only be returned if the request id is supported. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2018-01-089pfs: fix type in *_parse_opts declarationsGreg Kurz
To comply with the QEMU coding style. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2018-01-089pfs: handle: fix type definitionGreg Kurz
To comply with the QEMU coding style. Signed-off-by: Greg Kurz <groug@kaod.org>
2018-01-089pfs: fix some type definitionsGreg Kurz
To comply with the QEMU coding style. Signed-off-by: Greg Kurz <groug@kaod.org>
2018-01-089pfs: fix XattrOperations typedefGreg Kurz
To comply with the QEMU coding style. Signed-off-by: Greg Kurz <groug@kaod.org>
2018-01-08virtio-9p: move unrealize/realize after virtio_9p_transport definitionGreg Kurz
And drop the now useless forward declaration of virtio_9p_transport. Signed-off-by: Greg Kurz <groug@kaod.org>
2017-11-069pfs: fix v9fs_mark_fids_unreclaim() return valueGreg Kurz
The return value of v9fs_mark_fids_unreclaim() is then propagated to pdu_complete(). It should be a negative errno, not -1. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-11-069pfs: drop one user of struct V9fsFidStateGreg Kurz
To comply with QEMU coding style. Signed-off-by: Greg Kurz <groug@kaod.org>
2017-10-169pfs: use g_malloc0 to allocate space for xattrPrasad J Pandit
9p back-end first queries the size of an extended attribute, allocates space for it via g_malloc() and then retrieves its value into allocated buffer. Race between querying attribute size and retrieving its could lead to memory bytes disclosure. Use g_malloc0() to avoid it. Reported-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> Signed-off-by: Greg Kurz <groug@kaod.org>
2017-09-209pfs: check the size of transport buffer before marshalingJan Dakinevich
v9fs_do_readdir_with_stat() should check for a maximum buffer size before an attempt to marshal gathered data. Otherwise, buffers assumed as misconfigured and the transport would be broken. The patch brings v9fs_do_readdir_with_stat() in conformity with v9fs_do_readdir() behavior. Signed-off-by: Jan Dakinevich <jan.dakinevich@gmail.com> [groug, regression caused my commit 8d37de41cab1 # 2.10] Signed-off-by: Greg Kurz <groug@kaod.org>
2017-09-209pfs: fix name_to_path assertion in v9fs_complete_rename()Jan Dakinevich
The third parameter of v9fs_co_name_to_path() must not contain `/' character. The issue is most likely related to 9p2000.u protocol only. Signed-off-by: Jan Dakinevich <jan.dakinevich@gmail.com> [groug, regression caused by commit f57f5878578a # 2.10] Signed-off-by: Greg Kurz <groug@kaod.org>
2017-09-209pfs: fix readdir() for 9p2000.uJan Dakinevich
If the client is using 9p2000.u, the following occurs: $ cd ${virtfs_shared_dir} $ mkdir -p a/b/c $ ls a/b ls: cannot access 'a/b/a': No such file or directory ls: cannot access 'a/b/b': No such file or directory a b c instead of the expected: $ ls a/b c This is a regression introduced by commit f57f5878578a; local_name_to_path() now resolves ".." and "." in paths, and v9fs_do_readdir_with_stat()->stat_to_v9stat() then copies the basename of the resulting path to the response. With the example above, this means that "." and ".." are turned into "b" and "a" respectively... stat_to_v9stat() currently assumes it is passed a full canonicalized path and uses it to do two different things: 1) to pass it to v9fs_co_readlink() in case the file is a symbolic link 2) to set the name field of the V9fsStat structure to the basename part of the given path It only has two users: v9fs_stat() and v9fs_do_readdir_with_stat(). v9fs_stat() really needs 1) and 2) to be performed since it starts with the full canonicalized path stored in the fid. It is different for v9fs_do_readdir_with_stat() though because the name we want to put into the V9fsStat structure is the d_name field of the dirent actually (ie, we want to keep the "." and ".." special names). So, we only need 1) in this case. This patch hence adds a basename argument to stat_to_v9stat(), to be used to set the name field of the V9fsStat structure, and moves the basename logic to v9fs_stat(). Signed-off-by: Jan Dakinevich <jan.dakinevich@gmail.com> (groug, renamed old name argument to path and updated changelog) Signed-off-by: Greg Kurz <groug@kaod.org>
2017-09-059pfs: local: clarify fchmodat_nofollow() implementationGreg Kurz
Since fchmodat(2) on Linux doesn't support AT_SYMLINK_NOFOLLOW, we have to implement it using workarounds. There are two different ways, depending on whether the system supports O_PATH or not. In the case O_PATH is supported, we rely on the behavhior of openat(2) when passing O_NOFOLLOW | O_PATH and the file is a symbolic link. Even if openat_file() already adds O_NOFOLLOW to the flags, this patch makes it explicit that we need both creation flags to obtain the expected behavior. This is only cleanup, no functional change. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2017-09-059pfs: avoid sign conversion error simplifying the codePhilippe Mathieu-Daudé
(note this is how other functions also handle the errors). hw/9pfs/9p.c:948:18: warning: Loss of sign in implicit conversion offset = err; ^~~ Reported-by: Clang Static Analyzer Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Greg Kurz <groug@kaod.org>
2017-08-309pfs: fix dependenciesCornelia Huck
Nothing in fsdev/ or hw/9pfs/ depends on pci; it should rather depend on CONFIG_VIRTFS and CONFIG_VIRTIO/CONFIG_XEN only. Acked-by: Greg Kurz <groug@kaod.org> Reviewed-by: Thomas Huth <thuth@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2017-08-109pfs: local: fix fchmodat_nofollow() limitationsGreg Kurz
This function has to ensure it doesn't follow a symlink that could be used to escape the virtfs directory. This could be easily achieved if fchmodat() on linux honored the AT_SYMLINK_NOFOLLOW flag as described in POSIX, but it doesn't. There was a tentative to implement a new fchmodat2() syscall with the correct semantics: https://patchwork.kernel.org/patch/9596301/ but it didn't gain much momentum. Also it was suggested to look at an O_PATH based solution in the first place. The current implementation covers most use-cases, but it notably fails if: - the target path has access rights equal to 0000 (openat() returns EPERM), => once you've done chmod(0000) on a file, you can never chmod() again - the target path is UNIX domain socket (openat() returns ENXIO) => bind() of UNIX domain sockets fails if the file is on 9pfs The solution is to use O_PATH: openat() now succeeds in both cases, and we can ensure the path isn't a symlink with fstat(). The associated entry in "/proc/self/fd" can hence be safely passed to the regular chmod() syscall. The previous behavior is kept for older systems that don't have O_PATH. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com> Tested-by: Zhi Yong Wu <zhiyong.wu@ucloud.cn> Acked-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2017-07-31docs: fix broken paths to docs/devel/tracing.txtPhilippe Mathieu-Daudé
With the move of some docs/ to docs/devel/ on ac06724a71, no references were updated. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-07-13Convert error_report() to warn_report()Alistair Francis
Convert all uses of error_report("warning:"... to use warn_report() instead. This helps standardise on a single method of printing warnings to the user. All of the warnings were changed using these two commands: find ./* -type f -exec sed -i \ 's|error_report(".*warning[,:] |warn_report("|Ig' {} + Indentation fixed up manually afterwards. The test-qdev-global-props test case was manually updated to ensure that this patch passes make check (as the test cases are case sensitive). Signed-off-by: Alistair Francis <alistair.francis@xilinx.com> Suggested-by: Thomas Huth <thuth@redhat.com> Cc: Jeff Cody <jcody@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Max Reitz <mreitz@redhat.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Lieven <pl@kamp.de> Cc: Josh Durgin <jdurgin@redhat.com> Cc: "Richard W.M. Jones" <rjones@redhat.com> Cc: Markus Armbruster <armbru@redhat.com> Cc: Peter Crosthwaite <crosthwaite.peter@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Greg Kurz <groug@kaod.org> Cc: Rob Herring <robh@kernel.org> Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Peter Chubb <peter.chubb@nicta.com.au> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Marcel Apfelbaum <marcel@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Alexander Graf <agraf@suse.de> Cc: Gerd Hoffmann <kraxel@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Greg Kurz <groug@kaod.org> Acked-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed by: Peter Chubb <peter.chubb@data61.csiro.au> Acked-by: Max Reitz <mreitz@redhat.com> Acked-by: Marcel Apfelbaum <marcel@redhat.com> Message-Id: <e1cfa2cd47087c248dd24caca9c33d9af0c499b0.1499866456.git.alistair.francis@xilinx.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-06-299pfs: handle transport errors in pdu_complete()Greg Kurz
Contrary to what is written in the comment, a buggy guest can misconfigure the transport buffers and pdu_marshal() may return an error. If this ever happens, it is up to the transport layer to handle the situation (9P is transport agnostic). This fixes Coverity issue CID1348518. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2017-06-29xen-9pfs: disconnect if buffers are misconfiguredStefano Stabellini
Implement xen_9pfs_disconnect by unbinding the event channels. On xen_9pfs_free, call disconnect if any event channels haven't been disconnected. If the frontend misconfigured the buffers set the backend to "Closing" and disconnect it. Misconfigurations include requesting a read of more bytes than available on the ring buffer, or claiming to be writing more data than available on the ring buffer. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Signed-off-by: Greg Kurz <groug@kaod.org>
2017-06-29virtio-9p: break device if buffers are misconfiguredGreg Kurz
The 9P protocol is transport agnostic: if the guest misconfigured the buffers, the best we can do is to set the broken flag on the device. Signed-off-by: Greg Kurz <groug@kaod.org>
2017-06-29virtio-9p: message header is 7-byte longGreg Kurz
The 9p spec at http://man.cat-v.org/plan_9/5/intro reads: "Each 9P message begins with a four-byte size field specify- ing the length in bytes of the complete message including the four bytes of the size field itself. The next byte is the message type, one of the constants in the enumeration in the include file <fcall.h>. The next two bytes are an iden- tifying tag, described below." ie, each message starts with a 7-byte long header. The core 9P code already assumes this pretty much everywhere. This patch does the following: - makes the assumption explicit in the common 9p.h header, since it isn't related to the transport - open codes the header size in handle_9p_output() and hardens the sanity check on the space needed for the reply message Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2017-06-29virtio-9p: record element after sanity checksGreg Kurz
If the guest sends a malformed request, we end up with a dangling pointer in V9fsVirtioState. This doesn't seem to cause any bug, but let's remove this side effect anyway. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
2017-06-299pfs: replace g_malloc()+memcpy() with g_memdup()Marc-André Lureau
I found these pattern via grepping the source tree. I don't have a coccinelle script for it! Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-06-299pfs: local: Add support for custom fmode/dmode in 9ps mapped security modesTobias Schramm
In mapped security modes, files are created with very restrictive permissions (600 for files and 700 for directories). This makes file sharing between virtual machines and users on the host rather complicated. Imagine eg. a group of users that need to access data produced by processes on a virtual machine. Giving those users access to the data will be difficult since the group access mode is always 0. This patch makes the default mode for both files and directories configurable. Existing setups that don't know about the new parameters keep using the current secure behavior. Signed-off-by: Tobias Schramm <tobleminer@gmail.com> Signed-off-by: Greg Kurz <groug@kaod.org>
2017-06-299pfs: local: remove: use correct path componentBruce Rogers
Commit a0e640a8 introduced a path processing error. Pass fstatat the dirpath based path component instead of the entire path. Signed-off-by: Bruce Rogers <brogers@suse.com> Signed-off-by: Greg Kurz <groug@kaod.org>
2017-05-259pfs: local: metadata file for the VirtFS rootGreg Kurz
When using the mapped-file security, credentials are stored in a metadata directory located in the parent directory. This is okay for all paths with the notable exception of the root path, since we don't want and probably can't create a metadata directory above the virtfs directory on the host. This patch introduces a dedicated metadata file, sitting in the virtfs root for this purpose. It relies on the fact that the "." name necessarily refers to the virtfs root. As for the metadata directory, we don't want the client to see this file. The current code only cares for readdir() but there are many other places to fix actually. The filtering logic is hence put in a separate function. Before: # ls -ld drwxr-xr-x. 3 greg greg 4096 May 5 12:49 . # chown root.root . chown: changing ownership of '.': Is a directory # ls -ld drwxr-xr-x. 3 greg greg 4096 May 5 12:49 . After: # ls -ld drwxr-xr-x. 3 greg greg 4096 May 5 12:49 . # chown root.root . # ls -ld drwxr-xr-x. 3 root root 4096 May 5 12:50 . and from the host: ls -al .virtfs_metadata_root -rwx------. 1 greg greg 26 May 5 12:50 .virtfs_metadata_root $ cat .virtfs_metadata_root virtfs.uid=0 virtfs.gid=0 Reported-by: Leo Gaspard <leo@gaspard.io> Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com> Tested-by: Leo Gaspard <leo@gaspard.io> [groug: work around a patchew false positive in local_set_mapped_file_attrat()]
2017-05-259pfs: local: simplify file openingGreg Kurz
The logic to open a path currently sits between local_open_nofollow() and the relative_openat_nofollow() helper, which has no other user. For the sake of clarity, this patch moves all the code of the helper into its unique caller. While here we also: - drop the code to skip leading "/" because the backend isn't supposed to pass anything but relative paths without consecutive slashes. The assert() is kept because we really don't want a buggy backend to pass an absolute path to openat(). - use strchrnul() to get a simpler code. This is ok since virtfs is for linux+glibc hosts only. - don't dup() the initial directory and add an assert() to ensure we don't return the global mountfd to the caller. BTW, this would mean that the caller passed an empty path, which isn't supposed to happen either. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com> [groug: fixed typos in changelog]
2017-05-259pfs: local: resolve special directories in pathsGreg Kurz
When using the mapped-file security mode, the creds of a path /foo/bar are stored in the /foo/.virtfs_metadata/bar file. This is okay for all paths unless they end with '.' or '..', because we cannot create the corresponding file in the metadata directory. This patch ensures that '.' and '..' are resolved in all paths. The core code only passes path elements (no '/') to the backend, with the notable exception of the '/' path, which refers to the virtfs root. This patch preserves the current behavior of converting it to '.' so that it can be passed to "*at()" syscalls ('/' would mean the host root). Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-05-259pfs: check return value of v9fs_co_name_to_path()Greg Kurz
These v9fs_co_name_to_path() call sites have always been around. I guess no care was taken to check the return value because the name_to_path operation could never fail at the time. This is no longer true: the handle and synth backends can already fail this operation, and so will the local backend soon. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-05-259pfs: assume utimensat() and futimens() are presentGreg Kurz
The utimensat() and futimens() syscalls have been around for ages (ie, glibc 2.6 and linux 2.6.22), and the decision was already taken to switch to utimensat() anyway when fixing CVE-2016-9602 in 2.9. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-05-259pfs: local: fix unlink of alien files in mapped-file modeGreg Kurz
When trying to remove a file from a directory, both created in non-mapped mode, the file remains and EBADF is returned to the guest. This is a regression introduced by commit "df4938a6651b 9pfs: local: unlinkat: don't follow symlinks" when fixing CVE-2016-9602. It changed the way we unlink the metadata file from ret = remove("$dir/.virtfs_metadata/$name"); if (ret < 0 && errno != ENOENT) { /* Error out */ } /* Ignore absence of metadata */ to fd = openat("$dir/.virtfs_metadata") unlinkat(fd, "$name") if (ret < 0 && errno != ENOENT) { /* Error out */ } /* Ignore absence of metadata */ If $dir was created in non-mapped mode, openat() fails with ENOENT and we pass -1 to unlinkat(), which fails in turn with EBADF. We just need to check the return of openat() and ignore ENOENT, in order to restore the behaviour we had with remove(). Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Eric Blake <eblake@redhat.com> [groug: rewrote the comments as suggested by Eric]
2017-05-259pfs: drop pdu_push_and_notify()Greg Kurz
Only pdu_complete() needs to notify the client that a request has completed. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2017-05-25virtio-9p/xen-9p: move 9p specific bits to core 9p codeGreg Kurz
These bits aren't related to the transport so let's move them to the core code. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2017-05-18Merge remote-tracking branch 'quintela/tags/migration/20170517' into stagingStefan Hajnoczi
migration/next for 20170517 # gpg: Signature made Wed 17 May 2017 11:46:36 AM BST # gpg: using RSA key 0xF487EF185872D723 # gpg: Good signature from "Juan Quintela <quintela@redhat.com>" # gpg: aka "Juan Quintela <quintela@trasno.org>" # Primary key fingerprint: 1899 FF8E DEBF 58CC EE03 4B82 F487 EF18 5872 D723 * quintela/tags/migration/20170517: migration: Move check_migratable() into qdev.c migration: Move postcopy stuff to postcopy-ram.c migration: Move page_cache.c to migration/ migration: Create migration/blocker.h ram: Rename RAM_SAVE_FLAG_COMPRESS to RAM_SAVE_FLAG_ZERO migration: Pass Error ** argument to {save,load}_vmstate migration: Fix regression with compression threads Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>