| Message ID | 20240801-tipic-overrun-v2-1-c5b869d1f074@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 6555a2a9212be6983d2319d65276484f7c5f431a |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,v2] tipc: guard against string buffer overrun | expand |
On Thu, Aug 01, 2024 at 07:35:37PM +0100, Simon Horman wrote: > Smatch reports that copying media_name and if_name to name_parts may > overwrite the destination. > > .../bearer.c:166 bearer_name_validate() error: strcpy() 'media_name' too large for 'name_parts->media_name' (32 vs 16) > .../bearer.c:167 bearer_name_validate() error: strcpy() 'if_name' too large for 'name_parts->if_name' (1010102 vs 16) > > This does seem to be the case so guard against this possibility by using > strscpy() and failing if truncation occurs. > > Introduced by commit b97bf3fd8f6a ("[TIPC] Initial merge") > > Compile tested only. > > Reviewed-by: Jakub Kicinski <kuba@kernel.org> > Signed-off-by: Simon Horman <horms@kernel.org> > --- > I am not marking this as a fix for net as I am not aware of this > actually breaking anything in practice. Thus, at this point I consider > it more of a clean-up than a bug fix. > --- > Changes in v2: > - Correct formatting and typo in subject (Thanks Jakub) > + The formatting problem was caused by tooling (b4) > so I reworded the subject as a work-around Just to clarify. The formatting issue I was referring, is a double space in the subject [1], which seems to of occurred due to the subject being linewrapped and then unlinewrapped. However, in the light of a new day, it is not at all clear to me that b4 is the cause of the problem. So sorry for pointing my finger at it. [1] https://lore.kernel.org/netdev/20240731182356.01a4c2b8@kernel.org/ > - Added Acked-by tag from Jakub > - Link to v1: https://lore.kernel.org/r/20240731-tipic-overrun-v1-1-32ce5098c3e9@kernel.org ...
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Thu, 01 Aug 2024 19:35:37 +0100 you wrote: > Smatch reports that copying media_name and if_name to name_parts may > overwrite the destination. > > .../bearer.c:166 bearer_name_validate() error: strcpy() 'media_name' too large for 'name_parts->media_name' (32 vs 16) > .../bearer.c:167 bearer_name_validate() error: strcpy() 'if_name' too large for 'name_parts->if_name' (1010102 vs 16) > > This does seem to be the case so guard against this possibility by using > strscpy() and failing if truncation occurs. > > [...] Here is the summary with links: - [net-next,v2] tipc: guard against string buffer overrun https://git.kernel.org/netdev/net-next/c/6555a2a9212b You are awesome, thank you!
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index 5a526ebafeb4..3c9e25f6a1d2 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -163,8 +163,12 @@ static int bearer_name_validate(const char *name, /* return bearer name components, if necessary */ if (name_parts) { - strcpy(name_parts->media_name, media_name); - strcpy(name_parts->if_name, if_name); + if (strscpy(name_parts->media_name, media_name, + TIPC_MAX_MEDIA_NAME) < 0) + return 0; + if (strscpy(name_parts->if_name, if_name, + TIPC_MAX_IF_NAME) < 0) + return 0; } return 1; }
Smatch reports that copying media_name and if_name to name_parts may overwrite the destination. .../bearer.c:166 bearer_name_validate() error: strcpy() 'media_name' too large for 'name_parts->media_name' (32 vs 16) .../bearer.c:167 bearer_name_validate() error: strcpy() 'if_name' too large for 'name_parts->if_name' (1010102 vs 16) This does seem to be the case so guard against this possibility by using strscpy() and failing if truncation occurs. Introduced by commit b97bf3fd8f6a ("[TIPC] Initial merge") Compile tested only. Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Simon Horman <horms@kernel.org> --- I am not marking this as a fix for net as I am not aware of this actually breaking anything in practice. Thus, at this point I consider it more of a clean-up than a bug fix. --- Changes in v2: - Correct formatting and typo in subject (Thanks Jakub) + The formatting problem was caused by tooling (b4) so I reworded the subject as a work-around - Added Acked-by tag from Jakub - Link to v1: https://lore.kernel.org/r/20240731-tipic-overrun-v1-1-32ce5098c3e9@kernel.org --- net/tipc/bearer.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)