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| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2015-11-06 05:50:51 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-06 06:34:48 +0300 |
| commit | fc5aeeaf593278f07ffa4d97296e27423ecae867 (patch) | |
| tree | 17b6521e9f9ba2d43d6d0b4d416d5a599e561980 /mm/kasan/report.c | |
| parent | f2377d4eaab2aabe1938b3974b5b94f5ba4c7ead (diff) | |
| download | linux-fc5aeeaf593278f07ffa4d97296e27423ecae867.tar.xz | |
mm/kasan: prevent deadlock in kasan reporting
When we end up calling kasan_report in real mode, our shadow mapping for
the spinlock variable will show poisoned. This will result in us calling
kasan_report_error with lock_report spin lock held. To prevent this
disable kasan reporting when we are priting error w.r.t kasan.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan/report.c')
| -rw-r--r-- | mm/kasan/report.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/mm/kasan/report.c b/mm/kasan/report.c index c5367089703c..7833f074ede8 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -173,12 +173,10 @@ static void print_shadow_for_address(const void *addr) * function, because generic functions may try to * access kasan mapping for the passed address. */ - kasan_disable_current(); memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW); print_hex_dump(KERN_ERR, buffer, DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1, shadow_buf, SHADOW_BYTES_PER_ROW, 0); - kasan_enable_current(); if (row_is_guilty(shadow_row, shadow)) pr_err("%*c\n", @@ -195,6 +193,10 @@ void kasan_report_error(struct kasan_access_info *info) { unsigned long flags; + /* + * Make sure we don't end up in loop. + */ + kasan_disable_current(); spin_lock_irqsave(&report_lock, flags); pr_err("=================================" "=================================\n"); @@ -204,12 +206,17 @@ void kasan_report_error(struct kasan_access_info *info) pr_err("=================================" "=================================\n"); spin_unlock_irqrestore(&report_lock, flags); + kasan_enable_current(); } void kasan_report_user_access(struct kasan_access_info *info) { unsigned long flags; + /* + * Make sure we don't end up in loop. + */ + kasan_disable_current(); spin_lock_irqsave(&report_lock, flags); pr_err("=================================" "=================================\n"); @@ -222,6 +229,7 @@ void kasan_report_user_access(struct kasan_access_info *info) pr_err("=================================" "=================================\n"); spin_unlock_irqrestore(&report_lock, flags); + kasan_enable_current(); } void kasan_report(unsigned long addr, size_t size, |