On Tue, 6 May 2025, Tudor Ambarus wrote:

The blammed commit copied to argv the size of the reallocated argv, instead of the size of the old_argv, thus reading and copying from past the old_argv allocated memory.

Following BUG_ON was hit: [ 3.038929][ T1] kernel BUG at lib/string_helpers.c:1040! [ 3.039147][ T1] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP ... [ 3.056489][ T1] Call trace: [ 3.056591][ T1] __fortify_panic+0x10/0x18 (P) [ 3.056773][ T1] dm_split_args+0x20c/0x210 [ 3.056942][ T1] dm_table_add_target+0x13c/0x360 [ 3.057132][ T1] table_load+0x110/0x3ac [ 3.057292][ T1] dm_ctl_ioctl+0x424/0x56c [ 3.057457][ T1] __arm64_sys_ioctl+0xa8/0xec [ 3.057634][ T1] invoke_syscall+0x58/0x10c [ 3.057804][ T1] el0_svc_common+0xa8/0xdc [ 3.057970][ T1] do_el0_svc+0x1c/0x28 [ 3.058123][ T1] el0_svc+0x50/0xac [ 3.058266][ T1] el0t_64_sync_handler+0x60/0xc4 [ 3.058452][ T1] el0t_64_sync+0x1b0/0x1b4 [ 3.058620][ T1] Code: f800865e a9bf7bfd 910003fd 941f48aa (d4210000) [ 3.058897][ T1] ---[ end trace 0000000000000000 ]--- [ 3.059083][ T1] Kernel panic - not syncing: Oops - BUG: Fatal exception

Fix it by copying the size of src, and not the size of dst, as it was.

Fixes: 5a2a6c428190 ("dm: always update the array size in realloc_argv on success") Cc: stable@vger.kernel.org Signed-off-by: Tudor Ambarus tudor.ambarus@linaro.org

---

drivers/md/dm-table.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 9e175c5e0634b49b990436898f63c2b1e696febb..6dae73ee49dbb36d89341ff09556876d0973c4ff 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -524,9 +524,9 @@ static char **realloc_argv(unsigned int *size, char **old_argv) } argv = kmalloc_array(new_size, sizeof(*argv), gfp); if (argv) {

• *size = new_size;
  

  if (old_argv) memcpy(argv, old_argv, *size * sizeof(*argv));

• *size = new_size;
  

  }

kfree(old_argv);

---

base-commit: 92a09c47464d040866cf2b4cd052bc60555185fb change-id: 20250506-dm-past-array-boundaries-1fe2f5a1030f

Best regards,

Tudor Ambarus tudor.ambarus@linaro.org

Thanks

I sent a pull request to Linus that includes this patch.

Mikulas