path: root/kernel/debug/kdb
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authorDaniel Thompson <daniel.thompson@linaro.org>2022-01-28 14:40:55 +0000
committerDaniel Thompson <daniel.thompson@linaro.org>2022-03-24 16:39:47 +0000
commitc1cb81429df462eca1b6ba615cddd21dd3103c46 (patch)
tree2aee1cbf8dd28849585f83aab94a9deefba254b8 /kernel/debug/kdb
parent09688c0166e76ce2fb85e86b9d99be8b0084cdf9 (diff)
kdb: Fix the putarea helper function
Currently kdb_putarea_size() uses copy_from_kernel_nofault() to write *to* arbitrary kernel memory. This is obviously wrong and means the memory modify ('mm') command is a serious risk to debugger stability: if we poke to a bad address we'll double-fault and lose our debug session. Fix this the (very) obvious way. Note that there are two Fixes: tags because the API was renamed and this patch will only trivially backport as far as the rename (and this is probably enough). Nevertheless Christoph's rename did not introduce this problem so I wanted to record that! Fixes: fe557319aa06 ("maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault") Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20220128144055.207267-1-daniel.thompson@linaro.org
Diffstat (limited to 'kernel/debug/kdb')
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c
index df2bface866e..85cb51c4a17e 100644
--- a/kernel/debug/kdb/kdb_support.c
+++ b/kernel/debug/kdb/kdb_support.c
@@ -291,7 +291,7 @@ int kdb_getarea_size(void *res, unsigned long addr, size_t size)
int kdb_putarea_size(unsigned long addr, void *res, size_t size)
- int ret = copy_from_kernel_nofault((char *)addr, (char *)res, size);
+ int ret = copy_to_kernel_nofault((char *)addr, (char *)res, size);
if (ret) {
kdb_func_printf("Bad address 0x%lx\n", addr);

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