kernel/linux.git/drivers/xen, branch v4.14.286

xen: unexport __init-annotated xen_xlate_map_ballooned_pages()

2022-07-02T14:18:10+00:00

commit dbac14a5a05ff8e1ce7c0da0e1f520ce39ec62ea upstream. EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic. modpost used to detect it, but it has been broken for a decade. Recently, I fixed modpost so it started to warn it again, then this showed up in linux-next builds. There are two ways to fix it: - Remove __init - Remove EXPORT_SYMBOL I chose the latter for this case because none of the in-tree call-sites (arch/arm/xen/enlighten.c, arch/x86/xen/grant-table.c) is compiled as modular. Fixes: 243848fc018c ("xen/grant-table: Move xlated_setup_gnttab_pages to common place") Reported-by: Stephen Rothwell Signed-off-by: Masahiro Yamada Reviewed-by: Oleksandr Tyshchenko Acked-by: Stefano Stabellini Link: https://lore.kernel.org/r/20220606045920.4161881-1-masahiroy@kernel.org Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

x86/xen: Remove undefined behavior in setup_features()

2022-07-02T14:18:08+00:00

[ Upstream commit ecb6237fa397b7b810d798ad19322eca466dbab1 ] 1 << 31 is undefined. So switch to 1U << 31. Fixes: 5ead97c84fa7 ("xen: Core Xen implementation") Signed-off-by: Julien Grall Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20220617103037.57828-1-julien@xen.org Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

xen/gnttab: fix gnttab_end_foreign_access() without page specified

2022-03-11T09:13:33+00:00

Commit 42baefac638f06314298087394b982ead9ec444b upstream. gnttab_end_foreign_access() is used to free a grant reference and optionally to free the associated page. In case the grant is still in use by the other side processing is being deferred. This leads to a problem in case no page to be freed is specified by the caller: the caller doesn't know that the page is still mapped by the other side and thus should not be used for other purposes. The correct way to handle this situation is to take an additional reference to the granted page in case handling is being deferred and to drop that reference when the grant reference could be freed finally. This requires that there are no users of gnttab_end_foreign_access() left directly repurposing the granted page after the call, as this might result in clobbered data or information leaks via the not yet freed grant reference. This is part of CVE-2022-23041 / XSA-396. Reported-by: Simon Gaiser Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich Signed-off-by: Greg Kroah-Hartman

xen: remove gnttab_query_foreign_access()

2022-03-11T09:13:33+00:00

Commit 1dbd11ca75fe664d3e54607547771d021f531f59 upstream. Remove gnttab_query_foreign_access(), as it is unused and unsafe to use. All previous use cases assumed a grant would not be in use after gnttab_query_foreign_access() returned 0. This information is useless in best case, as it only refers to a situation in the past, which could have changed already. Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich Signed-off-by: Greg Kroah-Hartman

xen/gntalloc: don't use gnttab_query_foreign_access()

2022-03-11T09:13:33+00:00

Commit d3b6372c5881cb54925212abb62c521df8ba4809 upstream. Using gnttab_query_foreign_access() is unsafe, as it is racy by design. The use case in the gntalloc driver is not needed at all. While at it replace the call of gnttab_end_foreign_access_ref() with a call of gnttab_end_foreign_access(), which is what is really wanted there. In case the grant wasn't used due to an allocation failure, just free the grant via gnttab_free_grant_reference(). This is CVE-2022-23039 / part of XSA-396. Reported-by: Demi Marie Obenour Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich Signed-off-by: Greg Kroah-Hartman

xen/grant-table: add gnttab_try_end_foreign_access()

2022-03-11T09:13:32+00:00

Commit 6b1775f26a2da2b05a6dc8ec2b5d14e9a4701a1a upstream. Add a new grant table function gnttab_try_end_foreign_access(), which will remove and free a grant if it is not in use. Its main use case is to either free a grant if it is no longer in use, or to take some other action if it is still in use. This other action can be an error exit, or (e.g. in the case of blkfront persistent grant feature) some special handling. This is CVE-2022-23036, CVE-2022-23038 / part of XSA-396. Reported-by: Demi Marie Obenour Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich Signed-off-by: Greg Kroah-Hartman

xen/xenbus: don't let xenbus_grant_ring() remove grants in error case

2022-03-11T09:13:32+00:00

Commit 3777ea7bac3113005b7180e6b9dadf16d19a5827 upstream. Letting xenbus_grant_ring() tear down grants in the error case is problematic, as the other side could already have used these grants. Calling gnttab_end_foreign_access_ref() without checking success is resulting in an unclear situation for any caller of xenbus_grant_ring() as in the error case the memory pages of the ring page might be partially mapped. Freeing them would risk unwanted foreign access to them, while not freeing them would leak memory. In order to remove the need to undo any gnttab_grant_foreign_access() calls, use gnttab_alloc_grant_references() to make sure no further error can occur in the loop granting access to the ring pages. It should be noted that this way of handling removes leaking of grant entries in the error case, too. This is CVE-2022-23040 / part of XSA-396. Reported-by: Demi Marie Obenour Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich Signed-off-by: Greg Kroah-Hartman

xen: detect uninitialized xenbus in xenbus_init

2021-12-08T07:46:48+00:00

commit 36e8f60f0867d3b70d398d653c17108459a04efe upstream. If the xenstore page hasn't been allocated properly, reading the value of the related hvm_param (HVM_PARAM_STORE_PFN) won't actually return error. Instead, it will succeed and return zero. Instead of attempting to xen_remap a bad guest physical address, detect this condition and return early. Note that although a guest physical address of zero for HVM_PARAM_STORE_PFN is theoretically possible, it is not a good choice and zero has never been validly used in that capacity. Also recognize all bits set as an invalid value. For 32-bit Linux, any pfn above ULONG_MAX would get truncated. Pfns above ULONG_MAX should never be passed by the Xen tools to HVM guests anyway, so check for this condition and return early. Cc: stable@vger.kernel.org Signed-off-by: Stefano Stabellini Reviewed-by: Juergen Gross Reviewed-by: Jan Beulich Link: https://lore.kernel.org/r/20211123210748.1910236-1-sstabellini@kernel.org Signed-off-by: Boris Ostrovsky Signed-off-by: Greg Kroah-Hartman

xen: don't continue xenstore initialization in case of errors

2021-12-08T07:46:48+00:00

commit 08f6c2b09ebd4b326dbe96d13f94fee8f9814c78 upstream. In case of errors in xenbus_init (e.g. missing xen_store_gfn parameter), we goto out_error but we forget to reset xen_store_domain_type to XS_UNKNOWN. As a consequence xenbus_probe_initcall and other initcalls will still try to initialize xenstore resulting into a crash at boot. [ 2.479830] Call trace: [ 2.482314] xb_init_comms+0x18/0x150 [ 2.486354] xs_init+0x34/0x138 [ 2.489786] xenbus_probe+0x4c/0x70 [ 2.498432] xenbus_probe_initcall+0x2c/0x7c [ 2.503944] do_one_initcall+0x54/0x1b8 [ 2.507358] kernel_init_freeable+0x1ac/0x210 [ 2.511617] kernel_init+0x28/0x130 [ 2.516112] ret_from_fork+0x10/0x20 Cc: Cc: jbeulich@suse.com Signed-off-by: Stefano Stabellini Link: https://lore.kernel.org/r/20211115222719.2558207-1-sstabellini@kernel.org Reviewed-by: Jan Beulich Signed-off-by: Boris Ostrovsky Signed-off-by: Greg Kroah-Hartman

xen-pciback: Fix return in pm_ctrl_init()

2021-11-26T10:40:35+00:00

[ Upstream commit 4745ea2628bb43a7ec34b71763b5a56407b33990 ] Return NULL instead of passing to ERR_PTR while err is zero, this fix smatch warnings: drivers/xen/xen-pciback/conf_space_capability.c:163 pm_ctrl_init() warn: passing zero to 'ERR_PTR' Fixes: a92336a1176b ("xen/pciback: Drop two backends, squash and cleanup some code.") Signed-off-by: YueHaibing Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20211008074417.8260-1-yuehaibing@huawei.com Signed-off-by: Boris Ostrovsky Signed-off-by: Sasha Levin