diff options
| author | Shigeru Yoshida <syoshida@redhat.com> | 2025-10-02 14:10:24 +0900 |
|---|---|---|
| committer | Marek Szyprowski <m.szyprowski@samsung.com> | 2025-10-03 08:44:06 +0200 |
| commit | ab220548dbefa8f99636741924b6fdf33f3230a2 (patch) | |
| tree | f5ebd7d8f9e75746d4e1e08a4040436693ffc9d5 /mm/kmsan/hooks.c | |
| parent | ef3d979b3e270b6a41b6f306bfc442253c41a4cd (diff) | |
kmsan: fix kmsan_handle_dma() to avoid false positives
KMSAN reports an uninitialized value issue in dma_map_phys()[1]. This
is a false positive caused by the way the virtual address is handled
in kmsan_handle_dma(). Fix it by translating the physical address to
a virtual address using phys_to_virt().
[1]
BUG: KMSAN: uninit-value in dma_map_phys+0xdc5/0x1060
dma_map_phys+0xdc5/0x1060
dma_map_page_attrs+0xcf/0x130
e1000_xmit_frame+0x3c51/0x78f0
dev_hard_start_xmit+0x22f/0xa30
sch_direct_xmit+0x3b2/0xcf0
__dev_queue_xmit+0x3588/0x5e60
neigh_resolve_output+0x9c5/0xaf0
ip6_finish_output2+0x24e0/0x2d30
ip6_finish_output+0x903/0x10d0
ip6_output+0x331/0x600
mld_sendpack+0xb4a/0x1770
mld_ifc_work+0x1328/0x19b0
process_scheduled_works+0xb91/0x1d80
worker_thread+0xedf/0x1590
kthread+0xd5c/0xf00
ret_from_fork+0x1f5/0x4c0
ret_from_fork_asm+0x1a/0x30
Uninit was created at:
__kmalloc_cache_noprof+0x8f5/0x16b0
syslog_print+0x9a/0xef0
do_syslog+0x849/0xfe0
__x64_sys_syslog+0x97/0x100
x64_sys_call+0x3cf8/0x3e30
do_syscall_64+0xd9/0xfa0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Bytes 0-89 of 90 are uninitialized
Memory access of size 90 starts at ffff8880367ed000
CPU: 1 UID: 0 PID: 1552 Comm: kworker/1:2 Not tainted 6.17.0-next-20250929 #26 PREEMPT(none)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-5.fc42 04/01/2014
Workqueue: mld mld_ifc_work
Fixes: 6eb1e769b2c1 ("kmsan: convert kmsan_handle_dma to use physical addresses")
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20251002051024.3096061-1-syoshida@redhat.com
Diffstat (limited to 'mm/kmsan/hooks.c')
| -rw-r--r-- | mm/kmsan/hooks.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/mm/kmsan/hooks.c b/mm/kmsan/hooks.c index 90bee565b9bc..2cee59d89c80 100644 --- a/mm/kmsan/hooks.c +++ b/mm/kmsan/hooks.c @@ -339,13 +339,12 @@ static void kmsan_handle_dma_page(const void *addr, size_t size, void kmsan_handle_dma(phys_addr_t phys, size_t size, enum dma_data_direction dir) { - struct page *page = phys_to_page(phys); u64 page_offset, to_go; void *addr; if (PhysHighMem(phys)) return; - addr = page_to_virt(page); + addr = phys_to_virt(phys); /* * The kernel may occasionally give us adjacent DMA pages not belonging * to the same allocation. Process them separately to avoid triggering |